Dr Bahman Amini Horri

Senior Lecturer in Chemical Engineering
MEng, MSc, CEng, CSci, MIChemE, PhD


Areas of specialism

Hydrogen production, water splitting, and thermochemical looping; Solid oxide fuel cells (SOFCs) and electrolysers; Ceramic nanocomposites and nanomaterial synthesis; Green synthesis of energy materials, ceramic nanocomposites, and catalysts; Alkaline electrolysers and flow cells

University roles and responsibilities

  • MSc Programmes Coordinator
  • IChemE Liaison of the CPE Department
  • The CPE Health and Safety Committee representative in the Department of Physics
  • Former AIO of the CPE Department
  • Green Hydrogen and Fuel Cell Research Cooridinator (Energy and Material Research Group)

    My qualifications

    PhD in Chemical Engineering
    Monash University (Australia)
    Master of Engineering Science (MSc) in Chemical Engineering
    Monash University (Australia)
    Master's Degree (MEng) in Chemical Engineering
    University of Tehran
    Bachelor’s Degree (BEng) in Chemical Engineering
    Iran University of Science and Technology
    Graduate Certificate in Learning and Teaching (GCLT)
    University of Surrey (United Kingdom)
    Graduate Certificate in Higher Education (GCHE)
    Monash University

    Previous roles

    2013 - 2016
    Monash University (Sunway Campus)
    2011 - 2012
    Teaching Associate
    Monash University (Clayton Campus)
    2001 - 2008
    Process Engineer
    Research Institute of Petroleum Industry (NIOC)

    In the media

    2018 Guildford Innovation Awards Celebrating Guildford’s Innovation Leaders Innovation Awards 2018 Salute Those Making Advances Within Technology and Sustainability   
    Winner of Innovate Guildford's award: Emerging Technologies “Tomorrow's World”: For an innovative technology in hydrogen generation
    Local media (Surrey)


    Research interests

    Research projects

    Indicators of esteem

    • Awards:

      2020:   IAAM: Award Lecture of the International Association of Advanced Materials, Sweden.

      2020:   InnoEnergy Award: Top 10% finalist in the 9th Call of Repsol Foundation’s Entrepreneurs Fund accelerator program, Germany.

      2018:   Innovation Award in Emerging Technologies: Tomorrow's World, Innovative Guildford, Surrey, UK.

      2012:   Postgraduate Publication Award, Monash University.

      2009:   Monash Graduate Scholarship (MGS), Monash University.

      2009:   Faculty of Engineering International Post Graduate Scholarship (FEIPRS), Monash University.

      1997:   The Best Industrial Trainee Award, Iran University of Science and Technology.

    • Patents:

      • UK Patent GB1811785.3, PCT/GB2019/052002 (2019): A Continuous Process for Sustainable Production of Hydrogen. filed on 19/07/2018. B.A. Horri, S. Gu.
      • UK Patent GB1710224.5, PCT/GB2018/051778 (2018): Hydrogen Generator. filed on 27/06/2017). B.A. Horri, S. Gu, M. Choolaei.
      • US Patent 9,206,050 B2 (2015): Continuous Process for Producing Carbon Nanotubes. A.M. Rashidi, B.A. Horri, A. Mohajeri, S. Sadraei Noori, K. Jafari Jozani, A. Nakhaeipor.
      • European Patent EP2196260 (2010), US Patent 20100167915 (2010): Hydrodesulphurization Nanocatalyst, Its Use and a Process for Its Production. A. Mohajeri, A.M. Rashidi, K. Jafari Jozani, P. Khorami, B. Amini Horri, D. Parviz, M. Kalbasi.
      • US Patent 7,491,750 (2009), also European Patent EP1754769 (2007): Continuous Catalyst/Wax Separation Method. H.R. Khakdaman, B.A. Horri, H. Manafi Varklani, S. Sadraei Noori.
    • Recent Presentations as the 'Invited Speaker'

      • B.A. Horri and S. Gu, “Development of a red‐ox process for sustainable production of hydrogen” H2FC Supergene Hub Conference - 2020, University of Nottingham, Nottingham, UK, 17 – 18, Feb 2020.
      • B.A. Horri, M.M. Choolaei, S. Gu, “Sustainable Production of Hydrogen Through a Metal/Metal-Oxide Loop”, EFCF 2019, The 23rd Conference in Series with Exhibition on Low-Temperature Fuel Cells, Electrolysers and H2 Processing, Fundamentals and Engineering Design, Lucerne, Switzerland, 2– 5 July 2019
      • B.A. Horri, “Lowering the temperature of solid oxide fuel cells”. The 13th of European SOFC & SOE Forum, Lucerne, Switzerland. 3 – 6 Jul 2018
      • B.A. Horri, “Synthesis and application of nanocomposite materials for ceramic fuel cells”, ICNN-2018, Tehran, IRAN, 26-28 Sep 2018.
      • B.A. Horri, “A highly efficient hydrogen generation electrolysis system using alkaline zinc hydroxide solution”. The 2nd International Conference on Advanced Energy Materials, AEM-2017, University of Surrey, England, 11 – 13 Sep 2017
      • B.A. Horri, “Gelling synthesis of NiO/YSZ nanocomposite powder for solid oxide fuel cells, The European Advanced Materials Congress, EAMC-2017, Stockholm, 22 – 24 Aug 2017.

    I am currently accepting self-funded PhD and volunteer research applicants in the field of hydrogen, fuel cell, and energy materials. You may contact me (b.aminihorri@surrey.ac.uk) to discuss the available topics/projects.  


    Postgraduate research supervision

    My teaching

    My publications



    Book Chapters:

    • M.M. Choolaei and B.A. Horri. "Catalytic aspects of fuel cells and electrolysers", In Heterogeneous catalysis for Energy applications, edited by T.R. Reina and J.A. Odriozola, In press (2020)
    • M.Y. Wong, B.A. Horri, B. Salamatinia, Chapter 8 – "Grafted Copolymerized Chitosan and Its Applications as a Green Biopolymer", In Biopolymer Grafting, edited by Vijay Kumar Thakur, Elsevier, Pages 285-333, (2018)
    • H.H. Lim, E. Sulistya, B. Salamatinia, and B.A. Horri "Ceramic Nanocomposites for Solid Oxide Fuel Cells". In "Sol-Gel Based Nanoceramic Material", Edited by Ajay Kumar Mishra, Springer (2017).
    • P. Amouzgar, M.Y. Wong, B.A. Horri, B. Salamatinia "Advanced material for pharmaceutical removal from wastewater". In "Smart Materials for Wastewater Application", Edited by Ajay Kumar Mishra, Wiley-Scrivener Publisher (2016).


    Y Zeng, K Wang, B Amini Horri, J Yao, Y Wu, D Li, HT Want (2011)Solar evaporation enhancement using floating light-absorbing magnetic particles, In: Energy & Environmental Science4(10)pp. 4074-4078 Royal Society of Chemistry

    We have demonstrated a new strategy for enhancing solar evaporation by using floating light-absorbing materials. Floating Fe3O4/C magnetic particles with an average size of 500 nm were synthesized by carbonization of poly(furfuryl alcohol) (PFA) incorporated with Fe3O4 nanoparticles. The Fe3O4/C particles had a BET surface area of 429 m2 g−1, and a density of 1.44 g cm−3. Because of their hydrophobicity and a bulk packing density of 0.53 g cm−3, Fe3O4/C particles were floatable on water. Our results indicated that these Fe3O4/C particles enhanced the water evaporation rate by as much as a factor of 2.3 in the solar evaporation of 3.5% salt water. In addition, Fe3O4/C particles were easily recycled using a magnet, and stable after being recycled three times. Our work provides a low-cost and highly effective way for accelerating solar evaporation for industrial applications such as solar desalination, salt production, brine management and wastewater treatment.

    B Amini Horri, CK Choo, TL Goh, L Shahcheraghi, GC Ngoh, AZ Abdullah, B Salamatinia (2016)Synthesis and Characterization of NiO Nano-Spheres by Templating on Chitosan as a Green Precursor, In: Journal of the American Ceramic Society99(12)pp. 3874-3882 Wiley

    In this study, nickel oxide was prepared through the calcination of extrusion dripped chitosan/nickel nitrate beads. The morphology and structural properties of the products were studied using various characterization techniques. Uniformly distributed nickel oxide was formed as observed from the studies of surface morphology where the processing parameters play a huge role on the resulting morphology. TEM results have shown that nickel oxide with crystallite sizes of 10–30 nm was obtained. The Fourier-transform infrared spectra studies show an intense peak at 525 cm−1, which is attributed to the vibration of Ni–O bond. Furthermore, the XRD results show NiO diffraction peaks correspond to (111), (200), (220), (311), and (222) which indicates that a bunsenite structure with a face-centered cubic phase was produced in this study. The usage of 500°C as the lower limit in this study is justified due to the complete removal of the templating material as seen in the thermalgravimetric analysis studies. Furthermore, it was obtained that the largest surface area of nickel oxide synthesized using this technique is 48.024 m2/g with pore sizes of 19.843 nm. The usage of chitosan as a green template for the synthesis of nanoparticles has shown promising results which allows a more economical and sustainable approach for the fabrication of nanomaterials.

    N Izadi, A Rashidi, B Amini Horri, MR Mosoudi, HR Bozorgzadeh, A Zeraatkar (2011)Growth of single-walled carbon nanotubes on a Co–Mo–MgO supported catalyst by the CVD of methane in a fixed bed reactor: Model setting and parameter estimation, In: Solid State Sciences13(6)pp. 1242-1250 Elsevier

    In this work methane was decomposed to hydrogen and carbon to determine its kinetic behavior during reaction over a Co–Mo–MgO supported catalyst using the CVD (Chemical Vapor Deposition) technique. Decomposition of methane molecules was performed in a continuous fixed bed reactor to obtain data to simulate methane decomposition in a gas phase heterogeneous media. The products and reactants of reaction were analyzed by molecular sieve column followed by GC-analysis of the fractions to determine the amount of product converted or reactant consumed. The synthesis of single-walled carbon nanotubes was performed at atmospheric pressure, different temperatures and reactant concentrations. The experimental data analyzed to suggest the formula for calculation of the initial specific reaction rate of the carbon nanotubes synthesis, were fitted by several mathematical models derived from different mechanisms based on Longmuir-hinshelwood expression. The suggested mechanism according to dissociation adsorption of methane seems to explain the catalytic performance in the range of operating conditions studied. The apparent activation energy for the growth of SWNTs was estimated according to Arrhenius equation. The as grown SWNTs products were characterized by SEM, TEM and Raman spectroscopy after purification. The catalyst deactivation was found to be dependent on the time, reaction temperature and partial pressure of methane and indicated that the reaction of deactivation can be modeled by a simple apparent second order of reaction.

    B Amini Horri, KB Tan, AZ Abdullah, B Salamatinia (2016)Adsorption Mechanism of Microcrystalline Cellulose as Green Adsorbent for the Removal of Cationic Methylene Blue Dye, In: JOURNAL OF THE CHEMICAL SOCIETY OF PAKISTAN38(4)pp. 651-664 The Chemical Society Of Pakistan

    The adsorption mechanism of pure cellulose is yet to be explored. Thus, in this study, the adsorption mechanism of Microcrystalline Cellulose (MCC), a polysaccharide which is renewable, low cost and non-toxic, was studied on the adsorption of model dye Methylene blue (MB). It was found that the main adsorption mechanism of MB on MCC was due to the electrostatic attraction between the positively charged MB dye and negatively charged MCC. Thus, physical adsorption was the dominant effect, since electrostatic attraction is categorized as physical adsorption. This was verified by Dubinin-Radushkevich isotherm, whereby mean free energy adsorption value was found to be less than 8 kJ/mol. The values of Gibbs free energy for thermodynamics studies were found to be within the range of -20 kJ/mol and 0 kJ/mol, which also indicated physical adsorption. It was due to the electrostatic attraction as adsorption mechanism of this adsorption process which resulted rapid adsorption of MB dye. It was found that equilibrium dye concentration was achieved between 1-3 minutes, depending on the adsorption temperature. The rapid adsorption, as compared to a lot of materials, showed the potential of MCC as the future of green adsorbent. The adsorption of Methylene Blue on MCC fitted well in Langmuir Isotherm, with R2 values of higher than 0.99, while fitted moderately in Freundlich Isotherm, with R2 values between 0.9224 and 0.9223. Comparatively, the adsorption of MB on MCC fitted best Langmuir Isotherm as compared to Freundlich Isotherm which monolayer adsorption occurred at the homogenous surface of MCC. This also indicated adsorbed MB molecules do not interact with each other at neighboring adsorption sites. The maximum adsorption capacity calculated from Langmuir Isotherm was found to be 4.95 mg/g. Despite the potential of MCC as green adsorbent, the challenge of low adsorption capacity has to be addressed in the future.

    B Amini Horri, P Amouzgar, MY Wong, B Salamatinia (2016)Advanced Material for Pharmaceutical Removal from Wastewater, In: Smart Materials for Waste Water Applicationspp. 179-212 John Wiley & Sons

    The 15 state-of-the-art review chapters contained in this book cover the recent advancements in the area of waste water, as well as the prospects about the future research and development of smart materials for the waste water applications ...

    Erick Sulistya, Lim Hui-Hui, Nicole K. Attenborough, Sara Pourshahrestani, Nahrizul Adib Kadri, Ehsan Zeimaran, Nasrul Anuar bin Abd Razak, Bahman Amini Horri, Babak Salamatinia (2020)Hydrothermal synthesis of carbon microspheres from sucrose with citric acid as a catalyst: physicochemical and structural properties, In: Journal of Taibah University for Science14(1)pp. 1042-1050

    The production of size-tunable Carbon microspheres (CMSs) from cheaply available materials using an environmentally friendly technique is highly appreciated. In this study, size-tunable CMSs were hydrothermally synthesized at 190°C using sucrose as carbon source, and citric acid as a catalyst. The effect of varying citric acid concentration on the size of the microspheres was investigated. Results indicated that under similar hydrothermal conditions, variation in the concentration of citric acid between 0 and 5 wt.% increased the size of CMSs ranging from 3.12 to 11.2 μm, as evidenced by SEM and particle size analyzer. TGA confirmed the purity of the carbonaceous particles in a single-step degradation with the presence of D-band and G-band in Raman spectra. FTIR and elemental analyzer confirmed the presence of hydrophilic oxygen functionalities such as –OH, –C=O, and COOH on the surface of CMSs. This study opens a novel and straightforward approach to produce size-tunable CMSs with functional groups.

    M-Y Wong, Bahman Amini Horri, B Salamatinia (2017)Grafted Copolymerized Chitosan and Its Applications as a Green Biopolymer, In: Biopolymer Grafting Applicationspp. 285-333 Elsevier

    Chitosan is a linear polysaccharide that can be synthesized through the deacetylation of chitin, a naturally abundant biopolymer found in the exoskeleton of crustaceans. It has received a lot of attention because of important features such as biodegradability, biocompatibility and antibacterial and regenerative properties. These features render it useful as the basic building block in important applications such as adsorptive wastewater treatment, sustained drug delivery, gene therapy, and electrosensors. Grafting this polymer with different types of moieties enhances its properties in different ways, e.g., grafting polyethylene glycol (PEG) to chitosan increases its solubility, and subsequently tuning the percent content of PEG imparts thermoresponsivity to the hydrogel. In this chapter, different applications of grafted chitosan are outlined with respect to different types of moieties, cross-linking reagents, grafting techniques, and experimental parameters such as the pH and the percent concentration of polymers.

    B Amini Horri, S Pezeshkpour, AZ Abdullah, B Salamatinia (2017)Ionic–gelation synthesis of gadolinium doped ceria (Ce0.8Gd0.2O1.90) nanocomposite powder using sodium-alginate, In: Ceramics International43(9)pp. 7123-7135 Elsevier

    Nanocomposite powders of gadolinium-doped ceria (GDC, Ce0.8Gd0.2O1.9) were synthesized via thermal treatment of the gel formed by contacting ionic solutions of sodium alginate as the jelling template and metal (gadolinium/cerium) nitrates as the starting material. The influence of calcination temperature and sodium alginate loading fraction on the properties of the synthesized GDC nanocomposite powders was investigated. Characterization was performed by energy dispersive X-ray spectroscopy, powder X-ray diffraction, thermogravimetric analysis, Field Emission Scanning Electron Microscopy, Fourier transformed infrared spectroscopy and nitrogen adsorption/desorption analysis. It was observed that the particle size and the surface area of the produced GDC nanocomposite powders are dominantly controlled by the calcination temperature, while the effect of sodium alginate loading fraction is limited by the range of the calcination temperature. In this study, the smallest mesoporous GDC nanocomposite powder with cubic fluorite structure (8 nm crystallite size and 3.05 ± 0.005 m2/g surface area) was synthesized using 2 wt. % of sodium alginate at a calcination temperature of 550 °C (for 4 h).The results of this study could help to perceive the influence of the basic processing variables on the particle size and the other physiochemical properties of GDC nanocomposite powders produced by the ionic-gelation method.

    Cameron Alexander Hurd Price, William Arnold, Laura Pastor-Perez, Bahman Amini-Horri, Tomas Ramirez Reina (2019)Catalytic upgrading of a biogas model mixture via low temperature DRM using multicomponent catalysts, In: Topics in Catalysis Springer Verlag

    The catalytic performance of a series of bimetallic Ni-Co/CeO2-Al2O3 catalysts were evaluated within the dry reforming of methane (DRM) reaction, commonly used for upgrading biogas. The study focused on the variation of CeO2 weight loadings between 0, 10, 20 and 30%. It was found that the addition of CeO2 promoted CH4 and CO2 conversion across the temperature range and increased H2/CO ratio for the “low temperature” DRM. X-Ray Diffraction (XRD), H2-Temperature Programmed Reduction (H2-TPR) and X-Ray Photoelectron Spectroscopy (XPS) analysis revealed the formation of Ce4+ during activation of the 30% sample, resulted in excessive carbon deposition during reaction. The lowest CeO2 weight loadings exhibited softer carbon formation and limited increased chemical stability during reaction at the expense of activity. Of the tested weight loadings, 20 wt% CeO2 exhibited the best balance of catalytic activity, chemical stability and deactivation resistance in the DRM reaction. Hence this catalyst can be considered a promising system for syngas production from biogas at relatively low temperatures evidencing the pivotal role of catalysts design to develop economically viable processes for bioresources valorisation.

    MM Montazer-Rahmati, B Amini Horri (2005)From laboratory experiments to design of a conveyor-belt dryer via mathematical modeling, In: Drying technology23(12)pp. 2389-2420 Taylor & Francis

    A conveyor-belt dryer for picrite has been modeled mathematically in this work. The necessary parameters for the system of equations were obtained from regression analysis of thin-layer drying data. The convective drying experiments were carried out at temperatures of 40, 60, 80, and 100°C and air velocities of 0.5 and 1.5 m/sec. To analyze the drying behavior, the drying curves were fitted to different semi-theoretical drying kinetics models such as those of Lewis, Page, Henderson and Pabis, Wang and Singh, and the decay models. The decay function (for second order reactions) gives better results and describes the thin layer drying curves quite well. The effective diffusivity was also determined from the integrated Fick's second law equation and correlated with temperature using an Arrhenius-type model. External heat and mass transfer coefficients were refitted to the empirical correlation using dimensionless numbers (J h , J D = m · Re n ) and their new coefficients were optimized as a function of temperature. The internal mass transfer coefficient was also correlated as a function of moisture content, air temperature, and velocity.

    Mohammadmehdi Choolaei, Tomas Ramirez Reina, Bahman Amini Horri (2020)Synthesis and characterisation of nanocrystalline CuO–Fe2O3/GDC anode powders for solid oxide fuel cells, In: Ceramics International Elsevier

    This paper deals with the development and potential application of a novel mixed ionic-electronic conductive anode composite comprised of copper and iron oxide based on gadolinium-doped ceria (CuO–Fe2O3/GDC) for solid-oxide fuel cell (SOFC). Synthesis of the nanocrystalline CuO–Fe2O3/GDC powders was carried out using a novel co-precipitation method based on ammonium tartrate as the precipitant in a mixed-cationic solution composed of Cu2+, Fe3+, Gd3+, and Ce3+. Thermal decomposition of the resultant precipitate after drying (at 55 °C) was investigated in a wide range of temperature (25–900 °C) using simultaneous DSC/TGA technique in air. The DSC/TGA results suggested the optimal calcination temperature of 500 °C for obtaining the nanocrystalline anode composite from the resultant precipitate. The synthesised CuO–Fe2O3/GDC samples were further characterised using XRD, dilatometry, FESEM, and EDX. Several single cells of SOFCs were fabricated in the anode-supported geometry using the synthesised CuO–Fe2O3/GDC composite as the anode, GDC/CuO composite as the electrolyte, and LSCF/GDC composite as the cathode layer. The fabricated cells were analysed using FESEM imaging and EIS analysis, where an equivalent circuit containing five R-CPE terms was used to interpret the EIS data. The module fitted well the impedance data and allowed for a detailed deconvolution of the total impedance spectra. The catalytic activity and uniformity of the synthesised nanocomposites was further evaluated using TPR analysis, demonstrating excellent activity at temperatures as low as 200 °C.

    Hui Hui Lim, Bahman Amini Horri, Babak Salamatinia (2018)Synthesis and Characterizations of Nickel (II) Oxide Sub-Micro Rods via co-precipitation Methods, In: IOP Conference Series: Materials Science and Engineering398(1)012033 IOP Publishing

    Co-precipitation method has been used for the synthesis of single crystalline Nickel (II) Oxide sub-micro rods. A two-step method was used to synthesise NiO sub-micro rods, in which the first step was the co-precipitation process Nickel (II) Nitrate with Ammonium Oxalate to form Nickel (II) Oxalate (NiC2O4), which is the precursor for the precipitates. The precipitate precursor then underwent the calcination process to form NiO sub-micro rods. Synthesized materials undergo Field Emission Scanning Electron Microscope (FESEM), particle size measurement via Zetasizer, elemental analysis via Energy-Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FT-IR) and Thermogravimetric Analysis (TGA). The morphology of NiO is found to have uniform rod- like crystals with mean z-diameter between 1600 nm to 2600 nm using Zetasizer.

    Kok Bing Tan, Alavy Kifait Reza, Ahmad Zuhairi Abdullah, Bahman Amini Horri, Babak Salamatinia (2018)Development of self-assembled nanocrystalline cellulose as a promising practical adsorbent for methylene blue removal, In: Carbohydrate Polymers199pp. 92-101 Elsevier

    This study is focused on nanocrystalline cellulose (NCC) flakes for methylene blue (MB) removal via adsorption. NCC flakes exhibit a high adsorption capacity (188.7 mg/g fixed at 0.7 g/L adsorbent dosage, 25 °C and pH 6) compared to other nanomaterials, such as carbon nanotube and other cellulosic materials, such as coffee husks. Unlike NCC powder, it was observed that NCC flakes can be easily separated from wastewater containing MB. Further adsorption studies were conducted on NCC flakes, and it was found that 0.7 g/L was the optimum adsorbent dosage, which fitted well with the Langmuir Isotherm. The mean free energy value from Dubinin-Radushkevich isotherm was less than 8 kJ/mol. ΔGo values at different temperatures were within the -20 kJ/mol to 0 kJ/mol range. In conclusion, NCC flakes is a promising and practical ‘green’ nanomaterial that can be further developed for industrial applications.

    Bahman Amini Horri, Mohammadmehdi Choolaei, Aneeb Chaudhry, Hassan Qaalib (2018)A Highly Efficient Hydrogen Generation Electrolysis System using Alkaline Zinc Hydroxide Solution, In: International Journal of Hydrogen Energy Elsevier

    Alkaline water electrolysis is a well-established conventional technique for hydrogen production. However, due to its relatively high energy consumption, the cost of hydrogen produced by this technique is still high. Here in this work, we report for the first time the application of alkaline zinc hydroxide solution (composed of sodium zincate and potassium zincate in NaOH and KOH solutions, respectively) as an efficient, simple and recursive electrolyte for producing clean hydrogen through a continuous dual-step electrolysis process. The ionic conductivity, electrodes current density, and hydrogen evolution rate were measured in a wide range of the electrolyte concentrations (0.1-0.59 M). Also, the cell efficiency was studied at different ranges of current density (0.09-0.25 A/cm2) and applied potential (1.8-2.2 V). Results indicated that the application of alkaline zinc hydroxide solution at the optimum electrolyte concentration can enhance the hydrogen evolution rate minimally by a factor of 2.74 (using sodium zincate) and 1.47 (using potassium zincate) compared to the conventional alkaline water electrolysers. The results of this study could be helpful to better understand the electrochemical behaviour of the alkaline water electrolysers when sodium zincate and potassium zincate are used as ionic activators for enhancing hydrogen evolution.

    Yuan Teng Foo, Ahmad Zuhairi Abdullah, Bahman Amini Horri, Babak Salamatinia (2018)Synthesis and characterisation of Y2O3 using ammonia oxalate as a precipitant in distillate pack co-precipitation process, In: Ceramics International44(15)pp. 18693-18702 Elsevier

    Pure cubic phase yttrium oxide or yttria (Y2O3) nanoparticles were successfully synthesised via the co-precipitation method in a distillate pack, followed by calcination of the precursor, yttrium oxalate (Y2(C2O4)3) in a furnace. The co-precipitation reaction temperature was varied between room temperature and 100 °C for various reaction durations ranging between 0.5 and 3 h. The as-synthesised precursor was characterised using a thermogravimetric analyser (TGA) and Fourier transform infrared spectrometer (FTIR). The Y2O3 nanoparticles obtained from the calcination of the precursor at various calcination conditions (temperature ranged from 500 to 800 °C for 2–8 h) were characterised using a field emission scanning electron microscope (FESEM), a transmission electron microscope (TEM), X-ray diffraction (XRD), FTIR, a Raman spectrometer, and Brunauer–Emmett–Teller analyser (BET). It was concluded from these characterisations that the optimum processing parameters for pure Y2O3 nanoparticles are co-precipitation reaction at 40 °C for 1 h, followed by calcination at 650 °C for 4 h. This method yielded semispherical Y2O3 nanoparticles with crystallite size ranging between 7 and 21 nm and a large specific surface area of 7.40 m2/g.

    B Amini Horri, A Mohajeri, AM Rashidi, K Jafari Jozani, P Khorami, D Parviz, M Kalbasi (2010)Hydrodesulphurization Nanocatalyst, Its Use and a Process for Its Production

    A nano-supported hydrodesulphurization (HDS) catalyst is prepared for hydrodesulphurization of hydrocarbonaceous feed stock. The catalyst can be prepared through different methods and also used under milder conditions than those required for conventionally used HDS catalysts, but can also function under other hydrodesulphurization operating conditions

    B Amini Horri, HH Lim, E Sulistya, B Salamatinia, MY Wong (2016)Ceramic Nanocomposites for Solid Oxide Fuel Cells, In: Sol-gel Based Nanoceramic Materials: Preparation, Properties and Applicationspp. 157-183 Springer

    This book summarizes recent research and development in the field of nanostructured ceramics and their composites.

    Yuan Teng Foo, Li Ting Foo, Ladan Shahcheragh, Bahman Amini Horri, Babak Salamatinia (2019)Green Synthesis and Characterization of High-Purity Monodispersed Cupric Oxide (CuO) Nanopowder, In: Key Engineering Materials801pp. 351-356 Trans Tech Publications

    In this study, high quality monodispersed nanocrystalline cupric oxide (CuO) nanopowder was prepared through novel sol-gel green synthesis method, assisted by sodium alginate (Na-ALG) as the green ionic exchange material. The morphology and structural properties of CuO nanopowders synthesized with and without the incorporation of extrusion dripping, at different Na-ALG solution concentrations and calcination temperatures, were studied using thermalgravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. Optimum synthesis conditions were identified, resulting in high-purity, monodispersed nanocrystalline CuO powder in the range of 9.92 – 12.4 nm, which could have a promising future in various applications.

    YT Foo, J Chan, N Cheng, A Abdullahi, Bahman Amini Horri, B Salamatinia (2017)Synthesis and characterization of NiO and Ni nanoparticles using nanocrystalline cellulose (NCC) as a template, In: Ceramics International43(18)pp. 16331-16339 Elsevier

    In this study, nanosized nickel oxide (NiO) and nickel (Ni) powders were synthesised via glycine-nitrate (GN) combustion process, assisted by nanocrystalline cellulose (NCC) as a template. Despite the unique morphology of NCC, it has yet to be applied as a sacrificial bio-template for GN combustion process. In addition, NiO and Ni nanoparticles were obtained at relatively low temperatures in this study, whereby the calcination temperatures were varied from 400 °C to 600 °C, with calcination durations of 2, 4, and 6 h. The morphological analysis of the resulting products were conducted using FESEM, which showed uniformly dispersed NiO and Ni particles with average crystallite size of 25 nm and 27 nm, respectively. These results were confirmed using X-ray diffraction (XRD) technique. The Raman and Fourier transform infrared (FTIR) spectra revealed that the molecular fingerprints of the samples were in agreement with each other. Further analyses revealed that samples calcined at 600 °C for 4 h showed the lowest particle size for pure NiO, whereas the lowest particle size for pure Ni was obtained at 400 °C for 4 h. The TGA results were also consistent with the XRD analysis, whereby pure Ni was initially formed and upon heating, had gradually converted into NiO.

    I Unal, S Meisuria, Mohammadmehdi Choolaei, Tomas Ramirez Reina, Bahman Amini Horri (2018)Synthesis and Characteristics of Nanocrystalline Ni1-xCoxO/GDC Powder as a Methane Reforming Catalyst for SOFCs, In: Ceramics International44(6)pp. 6851-6860 Elsevier

    This paper has described the application of nickel-doped catalytic constituents based on gadolinium-doped ceria (GDC) for fabrication of the solid-oxide fuel cell (SOFC) anode layer integrated with an in-situ methane-reforming layer (MRL). Nanocrystalline powders of Ni1-xCo3xO1+3x/GDC and Ni1-xCuxO/GDC with various compositions (x = 0.3, 0.5, 0.7) were synthesised using an ultrasound-assisted method followed by a thermal treatment to be applied for fabrication of the integrated MRL and the SOFC anode layer, respectively. Thermogravimetric analysis showed that the synthesized powders should be optimally calcined at 700 °C to exhibit improved crystallinity and catalytic activity. The morphological analysis showed the formation of nanocrystalline powders with particle size ranging from 4-86 nm that was confirmed by the crystal size analysis using XRD results. The elemental analysis by EDX indicated a successful distribution of the constituent ceramic and bimetallic phases after the addition of a sonication stage. The results of FT-IR and Raman spectroscopy confirmed lack of solvents residual after calcination that was in agreement with residual moisture content values obtained from TGA data. The fabricated anode-MRL bilayers had an adequate porosity (36.7%) and shrinkage (33.5%) after adding carbon particles as a pore former (at a loading fraction of 5.9 wt.%). The catalytic performance measurements of the MRL showed a methane conversion of 13% at maximum activity with a weight hour space velocity (WHSV) of 60 L/gh that was mainly due to carbon deposition in the reaction condition.

    S Pezeshkpour, B Salamatinia, Bahman Amini Horri (2017)Synthesis and Characterization of Nanocrystalline NiO-GDC via sodium alginate- mediated ionic sol gel method, In: Ceramics International44(3)pp. 3201-3210 Elsevier

    In this study, nanocrystalline nickel oxide gadolinium-doped ceria (NiO-GDC) powder was synthesized using an ionic sol-gel method. The effects of calcination time and temperature on the particle size and the physiochemical properties of nanocrystalline NiO-GDC are presented in this paper. Using this method, gel beads were formed by contacting sodium alginate solution as the gelling template and metal (gadolinium/cerium/Ni) nitrates as the precursor. The obtained nanocrystallites were characterized using Field Emission Scanning Electron Microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, thermo gravimetric analysis, nitrogen adsorption/desorption analysis, and Fourier transform infrared spectroscopy. It was observed that the increasing calcination temperature had affected both the particle size and the surface area of the NiO-GDC, whereas the increasing calcination time had only impacted the size of the particles. The smallest mesoporous nanocrystalline NiO-GDC powder (12.1225 ± 0.005 m2/g surface area), composed of cubic GDC (5.18 nm crystallite size) and cubic NiO (7.99 nm crystallite size) were synthesized at a calcination temperature of 500 °C for 2 hours. This study hopes to inspire more researches on the ionic-gelation method for synthesizing other metal nanostructures as well as other reaction parameters.

    Yuan-Teng Foo, Ahmad Zuhairi Abdullah, Bahman Amini Horri, Babak Salamatinia (2019)Ammonium oxalate-assisted synthesis of Gd2O3 nanopowders, In: Ceramics International45(7)pp. pp 9082-9091 Elsevier

    The impacts of co-precipitation reaction temperature and duration, as well as calcination temperature and duration, on the particle morphology and properties of gadolinia (Gd2O3) nanopowders were investigated. Thermogravimetric curve of thermally treated gadolinium oxalate (Gd2(C2O4)3) showed that pure stable cubic phase Gd2O3 nanopowders could be obtained by calcining at 640 °C and higher. This finding was also supported by results obtained from Fourier Transform Infrared Spectrometry (FTIR) and Raman spectrometry. This study also shows that uniform spherules of Gd2O3 nanopowders could be obtained under controlled synthesis conditions. However, with an increase in both the co-precipitation reaction temperature and duration, the extent of agglomeration of Gd2O3 nanopowders increased, as observed under a Field Emission Scanning Electron Microscope (FESEM). The FESEM images and X-ray Diffraction (XRD) patterns also revealed accelerated grain growth and increased average crystallite size at high calcination temperatures and holding times. It was determined that the most favourable Gd2O3 particle morphology was achieved when Gd2(C2O4)3 was co-precipitated at 40 °C, then thermally degraded at 650 °C, for 1 h and 4 h, respectively. Estimated Scherrer's average crystallite size of the resulting Gd2O3 nanopowders was 16.54 nm, which was further affirmed with the transmission electron microscope (TEM) image, where crystallite sizes of 3–27.5 nm were observed in the Gd2O3 sample. This specimen also demonstrated a considerably large specific surface area of 9.16 m2/g, as measured using a Brunauer–Emmett–Teller (BET) analyser.

    HUI-HU LIM, PHEY-NEE CHUA, HANG PUI MUN, Bahman Amini Horri, BABAK SALAMATINIA (2019)SYNTHESIS AND CHARACTERISATION OF CuO/HNT NANO-PARTICLES THROUGH IN-SITU GLYCINE NITRATE PROCESS, In: International Journal of Advances in Science Engineering and Technology6(2) Institute of Research and Journals

    Transition metal oxides have various interesting properties, especially nanostructures of the Copper (II) Oxides (CuO) have special magnetic properties and larger surface area which enhance the applications of the CuO in various fields. In this study, CuO nanoparticles supported on Halloysite Nanotubes (HNTs) via an in-situ glycine nitrate process was successfully synthesized by templating on chitosan. Effects of calcination time and temperature are fully elaborated by detail charactrizations including, FESEM, FTIR, TGA, EDX, BET and Raman Spectroscopy. The best calcination condition was found to be at 600 C for 5 h of calcination duration. Charactrizations confirmed the presence of both HNT and CuO within the particles confirming that the in-situ synthesis of metal-oxides by supporting them on HNTs is very much feasible.

    Amideddin Nouralishahi, Yadollah Mortazavi, Abbas Ali Khodadadi, Mohammadmehdi Choolaei, Levi T. Thompson, Bahman Amini Horri (2019)Characteristics and performance of urea modified Pt-MWCNTs for electro-oxidation of methanol, In: Applied Surface Science467-8pp. 335-344 Elsevier

    Multiwall carbon nanotubes are modified by urea (MWCNTs-U), as an amide group, through a simple amination method to be used as support for Pt nanoparticles in methanol electrooxidation reaction (MOR). The amination method involves a covalent grafting of urea molecules onto the surface of acid treated multiwall carbon nanotubes (MWCNTs-A) using O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU) as the coupling agent. Platinum nanoparticles are impregnated on the surface of MWCNTs-U using NaBH4. Pt/MWCNTs-U shows an enhanced electrocatalytic activity and durability with exposing larger accessible surface area and 27% higher active surface area compared to Pt/MWCNTs-A. In addition, urea incorporation can improve the electrocatalyst tolerance against CO-poisoning, due to the enhanced formation kinetics of the chemisorbed hydroxyl groups. The onset potential of COads oxidation indicates a decrease from 553 mV to 530 mV for Pt/MWCNTs-A and Pt/MWCNTs-U, respectively. It is observed that in the presence of amide group the forward peak current density and exchange current density, in CV and LSV experiments, respectively increase from 378 to 515 mA/mgPt and 1.59 × 10−8 A/cm2 to 2.12 × 10−8 A/cm2. These results are also in a good agreement with the theoretical activation energies obtained from Arrhenius plots, indicating a decrease from 41.7 to 38.8 kJ/mol methanol in the case of Pt/MWCNTs-A and Pt/MWCNTs-U, respectively.

    Nasrin Ghaemi, Robert C.T Slade, Bahman Amini Horri (2021)A benzoate coprecipitation route for synthesizing nanocrystalline GDC powder with lowered sintering temperature, In: Ceramics international Elsevier Ltd

    Electrolyte powders with low sintering temperature and high-ionic conductivity can considerably facilitate the fabrication and performance of solid oxide fuel cells (SOFCs). Gadolinia-doped ceria (GDC) is a promising electrolyte for developing intermediate- and low-temperature (IT and LT) SOFCs. However, the conventional sintering temperature for GDC is usually above 1200 °C unless additives are used. In this work, a nanocrystalline powder of GDC, (10 mol% Gd dopant, Gd0.1Ce0.9O1.95) with low-sintering temperature has been synthesized using ammonium benzoate as a novel, environmentally friendly and cost-effective precursor/precipitant. The synthesized benzoate powders (termed washed- and non-washed samples) were calcined at a relatively low temperature of 500 °C for 6 h. Physicochemical characteristics were determined using thermal analysis (TG/DTA), Raman spectroscopy, FT-IR, SEM/EDX, XRD, nitrogen absorptiometry, and dilatometry. Dilatometry showed that the newly synthesized GDC samples (washed and non-washed routes) start to shrink at temperatures of 500 and 600 °C (respectively), reaching their maximum sintering rate at 650 and 750 °C. Sintering of pelletized electrolyte substrates at the sintering onset temperature for commercial GDC powder (950 °C) for 6 h, showed densification of washed- and non-washed samples, obtaining 97.48 and 98.43% respectively, relative to theoretical density. The electrochemical impedance spectroscopy (EIS) analysis for the electrolyte pellets sintered at 950 °C showed a total electrical conductivity of 3.83 × 10−2 and 5.90 × 10−2 S cm−1 (under air atmosphere at 750 °C) for washed- and non-washed samples, respectively. This is the first report of a GDC synthesis, where a considerable improvement in sinterability and electrical conductivity of the product GDC is observed at 950 °C without additives addition.

    The disclosure provides a method of producing hydrogen. The method comprises conducting a thermochemical reaction by contacting a metal, or an alloy thereof, with steam to produce a metal oxide and/or a metal hydroxide and hydrogen. The method then comprises contacting the metal oxide and/or the metal hydroxide produced in the thermochemical reaction with water or a basic aqueous solution to produce a solution comprising a metal ion. Finally, the method comprises conducting an electrochemical reaction by applying a voltage across an anode and a cathode, whereby at least a portion of the cathode contacts the solution comprising the metal ion, to produce hydrogen, oxygen and the metal, or the alloy thereof.

    BAHMAN AMINI HORRI (2020)Hydrogen Generator

    The disclosure relates to an electrolysis cell for producing hydrogen . The cell comprises an electrolyte compartment and an electrolyte disposed therein . The electrolyte com prises an aqueous alkaline solution comprising a transition metal ion or p block metal ion . The cell further comprises first and second spaced apart electrodes at least partially disposed in the electrolyte .

    Mohsen Fallah Vostakola, Bahman Amini Horri (2021)Progress in Material Development for Low-Temperature Solid Oxide Fuel Cells: A Review, In: Energies (Basel)14(5) MDPI

    Solid oxide fuel cells (SOFCs) have been considered as promising candidates to tackle the need for sustainable and efficient energy conversion devices. However, the current operating temperature of SOFCs poses critical challenges relating to the costs of fabrication and materials selection. To overcome these issues, many attempts have been made by the SOFC research and manufacturing communities for lowering the operating temperature to intermediate ranges (600–800 °C) and even lower temperatures (below 600 °C). Despite the interesting success and technical advantages obtained with the low-temperature SOFC, on the other hand, the cell operation at low temperature could noticeably increase the electrolyte ohmic loss and the polarization losses of the electrode that cause a decrease in the overall cell performance and energy conversion efficiency. In addition, the electrolyte ionic conductivity exponentially decreases with a decrease in operating temperature based on the Arrhenius conduction equation for semiconductors. To address these challenges, a variety of materials and fabrication methods have been developed in the past few years which are the subject of this critical review. Therefore, this paper focuses on the recent advances in the development of new low-temperature SOFCs materials, especially low-temperature electrolytes and electrodes with improved electrochemical properties, as well as summarizing the matching current collectors and sealants for the low-temperature region. Different strategies for improving the cell efficiency, the impact of operating variables on the performance of SOFCs, and the available choice of stack designs, as well as the costing factors, operational limits, and performance prospects, have been briefly summarized in this work.

    B Amini Horri, C Selomulya, HT Wang (2012)Modeling the influence of carbon spheres on the porosity of SOFC anode materials, In: J American Ceramic Society95(4)pp. 1261-1268

    The influence of fabrication pressure and other ceramic processing variables, including volumetric loading fraction and the particle size ratio of pore-forming agents, on the porosity of fabricated ceramic anodes, was investigated using an integrated experimental approach with mathematical modeling to differentiate the impacts of each parameter. Despite historic observation of the properties of ceramic bodies, to date, there is a lack of available models to accurately interpret the ceramic properties as a function of the processing variables. Herein, we focus on the open porosity of the solid oxide fuel cell anode prepared from NiO/YSZ (nickel oxide/yttria stabilized zirconia) as the ceramic powder and using CMS (carbon microspheres) as a pore-forming agent. A range of pore-former volumetric blend ratios (4.4%–44.6%) and different particle size ratios between NiO/YSZ and CMS (11.27, 4.29, and 0.26) were used, whereas the influence of the applied uni-axial fabrication pressure on the open porosity of sintered anode was studied in a range of atmospheric pressure up to 40 MPa. A good agreement was observed between the proposed model and the experimental data, implying that the approach could be used to determine the significant processing parameters to fabricate ceramics with desired porosity. The model could also be used to interpret the physical basis of pore formation when using a pore-forming agent in a fabricated porous ceramic body.

    Estelle Le Saché, Sarah Johnson, Laura Pastor-Pérez, Bahman Amini Horri, Tomas Reina (2019)Biogas Upgrading Via Dry Reforming Over a Ni-Sn/CeO2-Al2O3 Catalyst: Influence of the Biogas Source, In: Energies12(6) MDPI

    Biogas is a renewable, as well as abundant, fuel source which can be utilised in the production of heat and electricity as an alternative to fossil fuels. Biogas can additionally be upgraded via the dry reforming reactions into high value syngas. Nickel-based catalysts are well studied for this purpose but have shown little resilience to deactivation caused by carbon deposition. The use of bi-metallic formulations, as well as the introduction of promoters, are hence required to improve catalytic performance. In this study, the effect of varying compositions of model biogas (CH4/CO2 mixtures) on a promising multicomponent Ni-Sn/CeO2-Al2O3 catalyst was investigated. For intermediate temperatures (650 °C), the catalyst displayed good levels of conversions in a surrogate sewage biogas (CH4/CO2 molar ratio of 1.5). Little deactivation was observed over a 20 h stability run, and greater coke resistance was achieved, related to a reference catalyst. Hence, this research confirms that biogas can suitably be used to generate H2-rich syngas at intermediate temperatures provided a suitable catalyst is employed in the reaction.

    Yuan Teng Foo, Ahmad Zuhairi Abdullah, Bahman Amini Horri, Babak Salamatinia (2019)Optimised Co-Precipitation synthesis condition for oxalate-derived zirconia nanoparticles, In: Ceramics International45(17B)pp. 22930-22939 Elsevier

    Zirconia (ZrO₂) nanoparticles were successfully synthesised from zirconyl chloride and ammonium oxalate via co-precipitation (CP), followed by calcination of the resulting co-precipitated precursor. CP and calcination processing parameters showed considerable effects on the surface morphology, average crystallite size, and phase purity of the resulting ZrO₂ particles. In this work, field emission scanning and transmission electron microscopy (FESEM and TEM) confirmed the existence of spherical and uniformly shaped ZrO₂ particles, with crystallite size ranging between 6 and 35 nm. Pure ZrO₂ nanoparticles synthesised through calcination at 650 °C had a strained monoclinic phase structure. On the other hand, ZrO₂ particles prepared through calcination at 600 °C revealed presence of a transitional phase from tetragonal to monoclinic phase in its X-ray diffraction (XRD) patterns. The FESEM images and XRD results also revealed that the degree of particle agglomeration and average crystallite size had increased with increasing processing temperatures and durations. Henceforth, precursor was co-precipitated at 40 °C for 1 h, then calcined at 650 °C for 4 h for optimum production of ZrO₂ nanoparticles with an average crystallite size of 12.85 nm and large Brunauer–Emmett–Teller (BET) surface area of 18.06 m²/g.

    B Amini Horri, C Selomulya, HT Wang (2012)Characteristics of Ni/YSZ ceramic anode prepared using carbon microspheres as a pore former, In: International Journal of Hydrogen Energy37(20)pp. 15311-15319

    Microstructural features and physical properties of the anodes crucially affect the electrochemical performance of anode-supported solid oxide fuel cells (SOFCs). This paper evaluated the microstructural characteristics and properties including porosity, pore size distribution, sintering shrinkage, mechanical strength, and electrical conductivity of the SOFC anode using carbon microspheres (CMSs) as the pore-former in the fabrication of Ni/YSZ ceramic anode. CMSs with different average particle sizes (CMS1: 11.54 μm, CMS2: 4.39 μm, and CMS3: 0.27 μm) were synthesized, and then incorporated into NiO/YSZ at various volumetric blend ratios ranging from 4.4 to 44.6 vol.%. SOFC anode cermets with a desirable range of porosity (30–40%), shrinkage (15.9–17.3%), flexural strength (75.4–157.8 N), and electrical conductivity (253.5–510.7 S/cm) were obtained using approximately 4–10 vol% of CMS1, 4–20 vol.% of CMS2, and 10–34 vol.% of CMS3. In addition, the use of CMS as the pore former reduced the amount of closed pores in the anode disks from 2.05% to

    B Amini Horri, CK Choo, B Salamatinia (2016)Synthesis and Characterization of Nickel (II) Oxide/Gadolinium-Doped Ceria (NiO/GDC) Nanocomposites As a Potential Material for Anode Supported LT-SOFCs, In: Proceedings of the World Congress on Engineering and Computer ScienceII

    In this study, Ni-GDC Nano-powder was synthesized via ion-exchange technique using sodium alginate as the templating material. Nanoparticles were obtained by controlling the calcination temperature. FE-SEM showed that the particle size of the grain decreased with the increase in the calcination temperature. Furthermore, pure NiO-GDC structure was obtained at the calcination temperature of 500 C with no secondary phase present which is evident through the compositional characterization performed including XRD, FTIR and TGA analysis. The usage of ion-exchange sol gel technique has shown promising results to overcome high polarization observed at low operating temperature.

    CK Choo, YS Vivek, B Salamatinia, BA Horri, B Amini Horri (2017)Green Synthesis of ZnO Nanoparticles by an Alginate Mediated Ion-Exchange Process and a case study for Photocatalysis of Methylene Blue Dye, In: Journal of Physics: Conference Series829(1)

    n this study, zinc oxide (ZnO) was prepared via extrusion-dripping method through an ion exchange mediated process using sodium alginate. The samples were synthesized at 500 °C and 600 °C to study the effect of calcination temperature. The morphology, microstructure and optical activity of the calcined ZnO nanoparticles were analyzed by TGA, FESEM and XRD. It was found that ZnO nanoparticles synthesized at 600 °C was of higher purity with high crystallinity. To enhance the photocatalytic efficiency of zinc oxide, ZnO/NCC films were synthesized at varying ZnO loading fractions of 10 wt%, 15 wt%, 20 wt% and 25 wt% and were evaluated by photodegradation of Methylene blue dye and the highest dye percentage removal is found to be 96% which is obtained at ZnO loadings of 25 wt%. The usage of ion-exchange process has shown promising results in producing ZnO of desirable characteristics.

    B Amini Horri, D Dong, C Selomulya, HT Wang (2012)Rheological behaviour of NiO/YSZ slurries for drying-free casting, In: Powder Technology223pp. 116-122 Elsevier

    We have recently developed a new drying-free casting method for shape forming of ceramics, in which a polymerizable solvent such as furfuryl alcohol (FA) is used to disperse the ceramic powders, and then polymerized into a poly (furfuryl alcohol) (PFA) binder during the casting process. Compared with conventional casting processes, this method offers more flexibility in controlling the microstructure of ceramics and eliminates defects that are likely to arise from the drying step. Controlling the rheological behaviour of ceramic slurries is an important step in the casting process to achieve improved microstructural properties. In this study, the viscosity of slurries comprising NiO/YSZ (yttria stabilized zirconia) powders and FA as solvent was investigated over a wide range of shear rates (1 s− 1–1000 s− 1) and at different volumetric solid concentrations (from 20% to 70%), while the effects of dispersant were quantified by adding different amounts of PVP (polyvinyl pyrrolidone) between 1 wt.% and 4 wt.%. The minimum viscosity of NiO/YSZ/FA slurries could be achieved with 2 wt.% dispersant. The experimental data relating the changes in viscosity to the volumetric solid concentration were modeled using different viscosity models, with Liu's equation showing the best fit for NiO/YSZ/FA slurries with and without dispersant. The slurries showed a highly pseudoplastic behaviour without dispersant, while adding PVP as dispersant effectively modified the rheological behaviour toward Newtonian fluids.

    WH Lam, MN Chong, B Amini Horri, BT Tey, ES Chan (2017)Physicochemical stability of calcium-alginate beads immobilizing TiO2 nanoparticles for removal of cationic dye under UV irradiation, In: Journal of Applied Polymer Science

    Recently, there have been considerable interests to immobilize photocatalyst in alginate beads for removing pollutants from water sources. However, the feasibility of using alginate beads in industry largely depends on its long-term stability during operation. This study investigated the physicochemical stability of alginate/titanium dioxide beads (Alg/TiO2) when exposed to UV irradiation in aqueous environment. The degradation of Alg/TiO2 beads was evident because the diameter and mass of the beads was reduced by 12% and 40%, respectively, after 120 h of irradiation. A substantial amount of TiO2 was leached into the external medium. Consequently, the removal efficiency of model cationic dye was found to reduce after every process cycle. Morphological analysis showed the formation of cavities on the surface of the Alg/TiO2 beads. Interestingly, the blank alginate beads degraded more rapidly than the Alg/TiO2 beads, confirming the UV shielding effect of TiO2. Nevertheless, this study reveals the need to improve the UV stability of alginate-based beads before they can be considered for practical application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 133, 45002.

    Mohammadmehdi Choolaei, Qiong Cai, Robert C.T. Slade, Bahman Amini Horri (2018)Nanocrystalline gadolinium-doped ceria (GDC) for SOFCs by an environmentally-friendly single step method, In: Ceramics International44(11)pp. 13286-13292 Elsevier

    Nanocrystalline gadolinium-doped ceria (GDC) was synthesized by a single step, low cost and environmentally friendly method using ammonium tartrate as an inexpensive, green and novel precipitant. The precipitate obtained during the process was calcined at 400 and 600 °C and the effect on the final microstructural properties of the powders of differing process variables were studied. The synthesized GDC samples were analysed using a range of different techniques, including XRD, TG/DSC, FESEM, STEM, and FT-IR and Raman spectroscopies. The thermal (TG/DSC), XRD and Raman spectroscopic analyses confirm the formation of a single crystalline phase with a cubic (fluorite) unit cell and formed at a low calcination temperature (400 °C). XRD profiles permitted estimation of crystallite sizes as

    Cameron Price, William Arnold, Laura Pastor-Perez, Bahman Amini-Horri, Thomas R. Reina (2020)Catalytic upgrading of a biogas model mixture via low temperature DRM using multicomponent catalysts., In: Topics in Catalysis Springer Verlag

    The catalytic performance of a series of bimetallic Ni-Co/CeO2-Al2O3 catalysts were evaluated within the dry reforming of methane (DRM) reaction, commonly used for upgrading biogas. The study focused on the variation of CeO2 weight loadings between 0, 10, 20 and 30%. It was found that the addition of CeO2 promoted CH4 and CO2 conversion across the temperature range and increased H2/CO ratio for the “low temperature” DRM. X-Ray Diffraction (XRD), H2-Temperature Programmed Reduction (H2-TPR) and X-Ray Photoelectron Spectroscopy (XPS) analysis revealed the formation of Ce4+ during activation of the 30% sample, resulted in excessive carbon deposition during reaction. The lowest CeO2 weight loadings exhibited softer carbon formation and limited increased chemical stability during reaction at the expense of activity. Of the tested weight loadings, 20 wt% CeO2 exhibited the best balance of catalytic activity, chemical stability and deactivation resistance in the DRM reaction. Hence this catalyst can be considered a promising system for syngas production from biogas at relatively low temperatures evidencing the pivotal role of catalysts design to develop economically viable processes for bioresources valorisation.