Effect of calcination temperature on the performance of hexaaluminate supported CeO2 for chemical looping dry reforming

The chemical looping dry reforming (CLDR) of methane is a novel syngas production and CO2 utilization technology via the circulation of oxygen carrier. In this work, BaFe3Al9O19 (BF3) hexaaluminate supported CeO2 serves as oxygen carrier for CLDR. Combined with a series of characterization, the effect of interaction between CeO2 and hexaaluminate as a function of calcination temperatures (700, 800, 900 and 1000 degrees C) on the CLDR performance was carefully investigated, and then the possible reaction mechanism was proposed. The results show that fresh CeO2/BF3 is composed of CeO2, beta-Al2O3 and magnetoplumite (MP) hexaaluminate. Increasing the calcination temperature from 700 to 900 degrees C is conducive to enhancing the interaction strength between CeO2 and hexaaluminate, which favors the diffusion of lattice oxygen to the surface. However, 1000. C calcination leads to the sintering of oxygen carrier, which hinders the migration of lattice oxygen. Among CeO2/BF3-T (T = 700-1000 degrees C), CeO2/BF3-900 degrees C presents not only a high methane conversion (similar to 85%), high syngas yield (1.28-2.02 mmol/g) with ideal H-2/CO ratio (similar to 2), but also excellent CO2 activation ability and cyclic stability in the periodic CH4/CO2 redox cycles. The results were mainly attributed to the highest concentration of Ce3+ and Fe2+, abundant oxygen vacancies and the formation of CeFexAl1-xO3.

Automated summary

The study investigated the effect of the interaction between CeO2 and BF3 during calcination on the performance of chemical looping dry reforming. It was found that CeO2/BF3 calcined at 900 degrees Celsius showed the best catalytic performance.