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Qi Zhang


Postgraduate Research Student

My research project

My publications

Publications

S Marson, RA Dorey, Q Zhang, RW Whatmore, A Hardy, J Mullens (2004)Direct patterning of photosensitive chemical solution deposition PZT layers, In: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY24(6)pp. 1925-1928
SG Wang, PJ Sellin, A Lohstroh, Q Zhang (2005)Performance improvement of polycrystalline diamond ultraviolet photodetectors by room-temperature plasma treatment, In: APPLIED PHYSICS LETTERS86(9)ARTN 0pp. ?-? AMER INST PHYSICS
DJ Yang, SG Wang, Q Zhang, PJ Sellin, G Chen (2004)Thermal and electrical transport in multi-walled carbon nanotubes, In: PHYSICS LETTERS A329(3)pp. 207-213 ELSEVIER SCIENCE BV
Qi Zhang, L. Pastor-Perez, S. Gu, Tomas Ramirez Reina (2020)Transition Metal Carbides (TMCs) catalysts for gas phase CO2 upgrading reactions: a comprehensive overview, In: Catalysts MDPI

Increasing demand for CO2 utilization reactions and the stable character of CO2 have motivated the interest in developing highly active, selective and stable catalysts. Precious metal catalysts have been studied extensively due to their high activities, but their implementation for industrial applications is hindered due to their elevated cost. Among the materials which have comparatively low prices, transition metal carbides (TMCs) are deemed to display catalytic properties similar to Pt-group metals (Ru, Rh, Pd, Ir, Pt) in several reactions such as hydrogenation and dehydrogenation processes. In addition, they are excellent substrates to disperse metallic particles. Hence, the unique properties of TMCs make them ideal substitutes for precious metals resulting in promising catalysts for CO2 utilization reactions. This work aims to provide a comprehensive overview of recent advances on TMCs catalysts towards gas phase CO2 utilization processes, such as CO2 methanation, reverse water gas shift (rWGS) and dry reforming of methane (DRM). We have carefully analyzed synthesis procedures, performances and limitations of different TMCs catalysts. Insights on material characteristics such as crystal structure and surface chemistry and their connection with the catalytic activity are also critically reviewed.

Srikanta Sannigrahi, Prashant Kumar, Anna Molter, Qi Zhang, Bidroha Basu, Arunima Sarkar Basu, Francesco Pilla (2021)Examining the status of improved air quality in world cities due to COVID-19 led temporary reduction in anthropogenic emissions, In: Environmental research196110927 Elsevier Inc

Clean air is a fundamental necessity for human health and well-being. Anthropogenic emissions that are harmful to human health have been reduced substantially under COVID-19 lockdown. Satellite remote sensing for air pollution assessments can be highly effective in public health research because of the possibility of estimating air pollution levels over large scales. In this study, we utilized both satellite and surface measurements to estimate air pollution levels in 20 cities across the world. Google Earth Engine (GEE) and Sentinel-5 Precursor TROPOspheric Monitoring Instrument (TROPOMI) application were used for both spatial and time-series assessment of tropospheric Nitrogen Dioxide (NO2) and Carbon Monoxide (CO) statuses during the study period (1 February to May 11, 2019 and the corresponding period in 2020). We also measured Population-Weighted Average Concentration (PWAC) of particulate matter (PM2.5 and PM10) and NO2 using gridded population data and in-situ air pollution estimates. We estimated the economic benefit of reduced anthropogenic emissions using two valuation approaches: (1) the median externality value coefficient approach, applied for satellite data, and (2) the public health burden approach, applied for in-situ data. Satellite data have shown that ~28 tons (sum of 20 cities) of NO2 and ~184 tons (sum of 20 cities) of CO have been reduced during the study period. PM2.5, PM10, and NO2 are reduced by ~37 (μg/m3), 62 (μg/m3), and 145 (μg/m3), respectively. A total of ~1310, ~401, and ~430 premature cause-specific deaths were estimated to be avoided with the reduction of NO2, PM2.5, and PM10. The total economic benefits (Billion US$) (sum of 20 cities) of the avoided mortality are measured as ~10, ~3.1, and ~3.3 for NO2, PM2.5, and PM10, respectively. In many cases, ground monitored data was found inadequate for detailed spatial assessment. This problem can be better addressed by incorporating satellite data into the evaluation if proper quality assurance is achieved, and the data processing burden can be alleviated or even removed. Both satellite and ground-based estimates suggest the positive effect of the limited human interference on the natural environments. Further research in this direction is needed to explore this synergistic association more explicitly.

Ana Belén Dongil, Qi Zhang, Laura Pastor-Pérez, Tomás Ramírez-Reina, Antonio Guerrero-Ruiz, Inmaculada Rodríguez-Ramos (2020)Effect of Cu and Cs in the β-Mo2C System for CO2 Hydrogenation to Methanol, In: Catalysts10(10)pp. 1213-1213 MDPI AG

Mitigation of anthropogenic CO2 emissions possess a major global challenge for modern societies. Herein, catalytic solutions are meant to play a key role. Among the different catalysts for CO2 conversion, Cu supported molybdenum carbide is receiving increasing attention. Hence, in the present communication, we show the activity, selectivity and stability of fresh-prepared β-Mo2C catalysts and compare the results with those of Cu/Mo2C, Cs/Mo2C and Cu/Cs/Mo2C in CO2 hydrogenation reactions. The results show that all the catalysts were active, and the main reaction product was methanol. Copper, cesium and molybdenum interaction is observed, and cesium promoted the formation of metallic Mo on the fresh catalyst. The incorporation of copper is positive and improves the activity and selectivity to methanol. Additionally, the addition of cesium favored the formation of Mo0 phase, which for the catalysts Cs/Mo2C seemed to be detrimental for the conversion and selectivity. Moreover, the catalysts promoted by copper and/or cesium underwent redox surface transformations during the reaction, these were more obvious for cesium doped catalysts, which diminished their catalytic performance.

FFC Duval, RA Dorey, Q Zhang, RW Whatmore (2003)Lead germanium oxide sinter-assisted PZT composite thick films, In: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY23(11)PII S0955-pp. 1935-1941 ELSEVIER SCI LTD
Qi Zhang, Laura Pastor Perez, Wei Jin, Sai Gu, Tomas Ramirez Reina (2019)Understanding the promoter effect of Cu and Cs over highly effective -Mo2C catalysts for the reverse water-gas shift reaction, In: Applied Catalysis B: Environmental244pp. 889-898 Elsevier

Mo2C is an effective catalyst for chemical CO2 upgrading via reverse water-gas shift (RWGS). In this work, we demonstrate that the activity and selectivity of this system can be boosted by the addition of promoters such as Cu and Cs. The addition of Cu incorporates extra active sites such as Cu+ and Cu0 which are essential for the reaction. Cs is an underexplored dopant whose marked electropositive character generates electronic perturbations on the catalyst’s surface leading to enhanced catalytic performance. Also, the Cs-doped catalyst seems to be in-situ activated due to a re-carburization phenomenon which results in fairly stable catalysts for continuous operations. Overall, this work showcases a strategy to design highly efficient catalysts based on promoted β-Mo2C for CO2 recycling via RWGS.

RW Whatmore, Q Zhang, CP Shaw, RA Dorey, JR Alcock (2007)Pyroelectric ceramics and thin films for applications in uncooled infra-red sensor arrays, In: PHYSICA SCRIPTAT129pp. 6-11