Effect of preparation method on the properties of Cu/ZnO catalyst in steam reforming of methanol

Abstract

Several methods (sol-gel method, co-precipitation, homogeneous-precipitation) have been comparatively examined for the preparation of binary Cu/ZnO-based catalysts with Cu/Zn molar ratios in 70/30, 50/50 and 30/70 copper acetate (Cu(CH[subscript 3]COO)[subscript 2]H[subscript 2] O) and zinc acetate (Zn(CH[subscript 3]COO)[subscript 2] 2H[subscript 2]O) and ethanol were used as precursor for preparation of Cu/ZnO catalyst by sol-gel method. For co-precipitation method were prepared by the addition rate of a mixed copper nitrate (Cu(NO[subscript 3])[subscript 2]) and zince nitrate (Zn(NO[subscript 3])[subscript 2]) solution with a sodium carbonate (Na[subscript 2]CO[subscript 3]) solution. For homogeneous precipitation method were prepared by urea instead of Na[subsccript 2]CO[subscript 3] solution. All Cu/ZnO catalysts were applied for the catalytic production of hydrogen by steam reforming of methanol (SRM). Homogeneous precipitation method is preferable for this reaction. Then, study effect of calcinations conditions. Cu/ZnO catalysts are calcined by various atmospheres. Gases were used as atmosphere as follows: nitrogen, oxygen, air and hydrogen. Cu/ZnO catalyst was calcined by hydrogen, is the higher activity than the other atmospheres. Physical and chemical properties of Cu/ZnO catalyst were characterized by various techniques including X-ray diffraction (XRD), BET surface area, N[subscript 2]O chemisorption, Thermal gravimetric and differential thermal analysis (TG/DTA), Transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR).