Recent advances and perspectives of perovskite-derived Ni-based catalysts for CO2reforming of biogas

Abstract

CO2 reforming of biogas (CRBG) is a promising renewable energy source to tackle the global energy demands and environmental challenges. Biogas (BG) is reformed to produce syngas on numerous catalysts, including transitional (Ni, Co, Fe, and Mo) and precious (Pt, Pd, Rh, and Ru) metals over various supports. However, catalyst deactivation due to the carbon deposition and trace amounts of H2S in BG is a significant barrier to commercializing the CRBG. Recently, perovskite oxide catalysts have gained interest due to their unique structural characteristics and articulating properties that favor CRBG for carbon-free operation. This review discusses the perovskite oxide catalysts in CO2 reforming, emphasizing structural stability, activity, and carbon deposition. The exsolved perovskite catalysts are reviewed as potential alternatives to the conventional LaNiO3, which suffers the structure break-down during the dry reforming. The exsolution of the catalysts offers numerous benefits such as structural stability, strong metal support interaction, oxygen storage capacity, and active small particle size with good dispersion, thus leading to better catalyst stability without deactivation in CRBG. However, catalyst reduction conditions dictate the particle size and activity of the catalysts. This review extensively covers the studies on different Ni-derived perovskites, the effect of partial doping of various metals (Ni, Co, Fe, Pt, Pd, and Rh), and mechanisms and related mixed-oxide systems.