Hydrogen Production from Steam Reforming of Ethanol over Pd Promoted ZnO/Al_2O_3 Catalysts

Pd promoted ZnO/Al2O3 catalysts were prepared by impregnation method.The hydrogen production performance upon the steam reforming of ethanol(SRE) over the prepared catalysts was evaluated with n(H2O):n(C2H5OH) of 3:1 at 450 °C and atmospheric pressure.The results show that H2 and CH3CHO were the main products during the SRE reaction over the prepared catalysts.Different from the ZnO/Al2O3 catalysts,the Pd promoted ZnO/Al2O3 catalysts favored C-C scission during the SRE and thus a higher C2H5OH conversion of 65% and a H2 selectivity of 55% were obtained over the prepared Pd promoted catalysts.BET,transmission electron microscopy(TEM),and thermogravimetry-differential scanning calorimetry-mass spectrometry(TG-DSC-MS) coupling techniques were used to analyze the coking behavior on the catalyst surface.We found that Pd promotion does not prevent the formation of coke on the ZnO/Al2O3 catalysts.