Promotion effect of nickel for Cu–Ni/γ-Al2O3 catalysts in the transfer dehydrogenation of primary aliphatic alcohols

Hydrogen Production by Ethanol Reforming on Supported Ni-Cu Catalysts

Supported bimetallic Ni-Cu catalysts with different Ni-Cu loadings on alumina (Al₂O₃), alumina-silica (Al₂O₃-SiO₂), alumina-magnesia (Al₂O₃-MgO), alumina-zinc oxide (Al₂O₃-ZnO), and alumina-lanthanum oxide (Al₂O₃-La₂O₃) were prepared and tested in ethanol steam reforming for the production of hydrogen (H₂). These catalysts were characterized by X-ray diffraction, H₂-temperature-programmed reduction, ammonia-temperature-programmed desorption, X-ray photoelectron spectroscopy, thermogravimetry, and differential scanning calorimetry. Cu addition improved the reducibility of NiO. Among the as-prepared catalysts, 30Ni5Cu/Al₂O₃-MgO and 30Ni5Cu/Al₂O₃-ZnO demonstrated much higher H₂ selectivity and excellent coke resistance compared to the other investigated catalysts. Over 30Ni5Cu/Al₂O₃-MgO and 30Ni5Cu/Al₂O₃-ZnO, the respective H₂ selectivity was 73.3 and 63.6% at 450 °C and increased to 94.0 and 95.2% at 600 °C. The strong interaction of Ni-Cu and Al₂O₃-ZnO (or Al₂O₃-MgO) led to the formation of smaller and highly dispersed CuO and NiO species on the carrier, which is conducive to improved catalytic performance. These Al₂O₃-MgO- and Al₂O₃-ZnO-supported bimetallic Ni-Cu materials can be promising catalysts for hydrogen production from ethanol steam reforming.