Beta zeolite supported Cu/Ni catalyst for hydrogen production through ethanol steam reforming

A group of multi-functional xCuyNi-ABZ catalysts supported on all-silicon Beta zeolite were prepared by an incipient wetness impregnation method. The xCuyNi-ABZ catalysts were characterized by a variety of techniques to obtain the information of their structures, the effect of different amounts of Cu and Ni active sites and understanding the reaction pathway. Compared with the traditional SiO₂ supported catalyst, the 2.5Cu2.5Ni-ABZ catalyst exhibited very good catalytic performance for the ethanol steam reforming, including 100% conversion of ethanol, high 67.23% H₂ selectivity (67.23%) and low by-product selectivity (CO=4.14%, CH₄=5.65%) at 450 ℃ due to the synergistic effects of Ni and Cu. The Cu sites preferentially facilitate the dehydrogenation of ethanol at the initial reaction step, and the Ni metal catalyzes subsequently dissociation of the C-C bond. With increase of reaction temperature, H₂ and CO₂ selectivity are progressively increased together with the significant decline of CO and CH₄ selectivity, which indicates that the dominant reaction is steam acetaldehyde reforming. This phenomenon suggests that there is a temperature-related competition between acetaldehyde decomposition and acetaldehyde steam reforming reaction. Moreover, the presence of Cu promoted the water-gas-shift reaction. The 2.5Cu2.5Ni-ABZ catalyst possesses good anti-sintering ability and anti-carbon deposition properties.