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.

Keywords

• CaL-DRM
• CO2 capture
• Carbon deposition
• Methane
• Hydrogen production