Methane Oxy-Steam Reforming Over a Highly Efficient Ni/Al2O3 Nanocatalyst Prepared by Microwave-Assisted Impregnation Method

An alumina-supported nickel catalyst was prepared by impregnation of Ni^2+ solution onto mesoporous alumina undermicrowave irradiation (denoted as M-Ni/Al2O3). For comparison, a catalyst with the same nickel content was prepared by conventional impregnation method (denoted as UM-Ni/Al2O3). Both M-Ni/Al2O3 and UM-Ni/Al2O3 catalysts were applied to the syngas (H2 + CO) production by methane oxy-steam reforming in order to investigate the effect of preparation method on the catalytic performance.The reaction experiments were performed in a fixed-bed continuous flow reactor under atmospheric pressure. M-Ni/Al2O3 catalyst exhibited higher methane conversion (XCH4: 0.94) than UM-Ni/Al2O3 (XCH4: 0.58) in the oxy-steam reforming reaction. In addition, the value of syngas yield in M-Ni/Al2O3 (3.21 mole per mole of methane) was almost twice that of one for UM-Ni/Al2O3 catalyst (1.59 moles per mole of methane). Various operating conditions, such as the influences of the O2/CH4 and H2O/CH4 feed ratios, temperature and GHSV on the methane conversion and yield of products were investigated. According to the structural characterization (FTIR, XRD, N2 adsorption/desorption, H2-TPR and TEM), the excellent catalytic performance of M-Ni/Al2O3 catalyst was reasonably attributed to the nano-sized and uniform distributed nickel species ( 6 nm) which interacted with the alumina support strongly.