Carbon-resistant bifunctional catalyst composed of LaFeO3 enhanced Ni-CaO for integrated CO2 capture and conversion

Abstract

Coupled calcium cycling and dry reforming of methane (CaL-DRM) process has garnered significant attention in recent years as a promising technique for the CO₂ capture and in-situ conversion. However, traditional Ni-CaO catalysts with substantial CaL-DRM activity are susceptible to severe carbon deposition, which greatly hinders their industrial application. A combination of sol-gel and impregnation methods to include LaFeO₃ into Ni-CaO to enhance CO₂ capture and conversion is utilized. The characterization results indicate that the incorporation of LaFeO₃ significantly improves the dispersion of Ni and CaO, increases the concentration of oxygen vacancies, effectively suppresses the sintering and carbon deposition, and improves the cycling stability of Ni-CaO. In addition, LaFeO₃ promotes the outward diffusion of lattice oxygen, thereby facilitating CO₂ capture and CH₄ conversion to syngas. At 700 ℃, up to 86.5 % CO₂ conversion, 87.6 % CO selectivity, and syngas yield close to the theoretical value of 1.0 were achieved over 5Ni-30CaO-LFO (30 wt% CaO). More importantly, the activity of catalyst remains almost unchanged after 30 cycles. This study introduces an innovative approach for CaL-DRM, showing significant potential for effective and stable CO₂ capture and in-situ conversion.