A study of Ni-Co/CeO2 catalyst derived from metal–organic framework for dry reforming of methane

Abstract

The efficacy of cobalt-doped, MOF-derived catalysts for dry reforming of methane (DRM) was examined. The focus was on the influence of varying nickel and cobalt molar ratios on catalytic performance. Three catalysts with Ni:Co ratios of 1:1, 1:0.5, and 0.5:1, were synthesized and tested with cerium oxide as a constant support. The DRM reaction was conducted at a low temperature of 700°C for 24 h. Despite the low reaction temperature, the catalyst containing an equimolar ratio of Ni and Co demonstrated the highest performance, achieving CO₂ and CH₄ conversions of 91% and 84%, respectively, with an H₂/CO ratio of 0.96. A decrease in the loading of either nickel or cobalt reduced catalytic activity. The better performance of the Ni:Co (1:1) catalyst compared to Ni:Co (1:0.5) and Ni:Co (0.5:1) catalysts can be attributed to its smallest cobalt crystallite size of 1.6 nm, indicating better metal dispersion compared to the other catalysts. Smaller crystallite sizes enhance the availability of active sites, improve metal–support interaction, and promote efficient CO₂ activation. This improved dispersion likely contributed to the superior catalytic performance and coke resistance observed in the Ni(1)-Co(1)-Ce catalyst. The findings emphasize the critical role of active metal loading in achieving optimal DRM performance in the design of MOF-derived multi-metallic catalysts for DRM.