Syngas Production from CO₂ Reforming and CO₂-steam Reforming of Methane over Ni/Ce-SBA-15 Catalyst

This study compares the catalytic performance of mesoporous 10 Ni/Ce-SBA-15 catalyst for CO₂ reforming and CO₂-steam reforming of methane reactions in syngas production. The catalytic performance of 10 Ni/Ce-SBA-15 catalyst for CO₂ reforming and CO₂-steam reforming of methane was evaluated in a temperature-controlled tubular fixed-bed reactor at stoichiometric feed composition, 1023 K and atmospheric pressure for 12 h on-stream with gas hourly space velocity (GHSV) of 36 L g_cat ^-1 h^-1. The 10 Ni/Ce-SBA-15 catalyst possessed a high specific BET surface area and average pore volume of 595.04 m² g^-1. The XRD measurement revealed the presence of NiO phase with crystallite dimension of about 13.60 nm whilst H₂-TPR result indicates that NiO phase was completely reduced to metallic Ni⁰ phase at temperature beyond 800 K and the reduction temperature relied on different degrees of metal-support interaction associated with the location and size of NiO particles. The catalytic reactivity was significantly enhanced with increasing H₂O/CO₂ feed ratio. Interestingly, the H₂/CO ratio for CO₂-steam reforming of methane varied between 1 and 3 indicated the occurrence of parallel reactions, i.e., CH₄ steam reforming giving a H₂/CO of 3 whilst reverse water-gas shift (RWGS) reaction consuming H₂ to produce CO gaseous product.