Solid solution of Ce1-xYxO2-δ supported nickel-based catalysts for auto-thermal reforming of acetic acid with high resistance to coking

Abstract

Nickel-based catalysts are widely applied in auto-thermal reforming (ATR) of acetic acid (HAc) to extract hydrogen, but the persistent issue of coking is still a concern. Herein, Ce1-xYxO2-δ solid solutions were obtained to support nickel and the catalytic activity for the ATR was examined. The results indicated that with Y species in CeO2 lattice, the Ce1-xYxO2-δ solid solution structures with lattice defects and cell dislocation were formed; Meanwhile, the strong nickel-support interaction effectively constrained aggregation of Ni0; In addition, the solid solution induced formation of oxygen vacancies, and facilitated transfer and activation of oxygen species (O*). The DFT analysis further evidences the lower formation energy of oxygen vacancy over the solid solution. Therefore, the optimized Ni0.8Ce1.76Y0.35O4.85±δ catalyst provided excellent stability for activity test (50 h), in which HAc conversion and H2 yield stabilized at 100% and 2.6 mol-H2/mol-HAc, respectively, without obvious coking.