Plasma-enhanced comparative hydrothermal and coprecipitation preparation of CuO/ZnO/Al2O3 nanocatalyst used in hydrogen production via methanol steam reforming

Abstract

The CuO/ZnO/Al2O3 nanocatalyst was synthesized using hydrothermal and coprecipitation methods. Then they were exposed to glow discharge plasma for 45min at 1000V. The performance of prepared nanocatalysts in conversion of methanol to hydrogen was investigated in steam reforming of methanol reaction. Various characterization techniques such as X-ray diffraction, field emission electron microscopy, particle size distribution, EDX-dot mapping, BET surface area and Fourier transform infrared spectroscopy were used in order to obtain physicochemical properties of synthesized nanocatalysts. XRD diffraction patterns showed that applying coprecipitation method and also glow discharge plasma, led to more dispersion of CuO (111) crystallite plate. FESEM images displayed that using non-thermal plasma assisted coprecipitation synthesis method caused to best surficial morphology and particle size distribution in CuO/ZnO/Al2O3 sample. EDX-dot mapping analysis demonstrated that the CuO/ZnO/Al2O3 sample had the most uniform dispersion of elements. Evaluation of catalytic performance indicated that plasma assisted coprecipitation synthesized CuO/ZnO/Al2O3 sample had the highest conversion of methanol and the lowest CO generation among other samples in the reaction. Stability assessment of the performance of CuO/ZnO/Al2O3 nanocatalyst represented that conversion of methanol and products selectivity were approximately constant through long term use in steam reforming of methanol reaction.