Design of Ru-Co/MgO-Al2O3 catalyst system for CO2 reforming of methane: Performance investigation concerning the Mg/Al ratio

This study explores the design of bimetallic Co-Ru nanoclusters deposited on surface-tuned mesoporous Mg-Al mixed oxide support for the CO2 reforming of methane (DRM) process. The evaporation-induced self-assembly technique was used to create a series of MgO-Al2O3 mixed oxide supports with various Mg/Al molar ratios. Co and Ru nanoclusters over the MgO-Al2O3 supports were decorated using a urea precipitation-deposition approach. Results revealed that the activity and stability of the DRM catalyst were substantially reliant on the Mg/Al molar ratio and Co-Ru metal combination. Among the series of Co-loaded catalysts, the best performance was obtained over an unpromoted CoMg20Al catalyst (20 wt.% Mg), with only a 10 % activity loss after 50 h of study. A modification of CoMg20Al by 0.5 wt.% Ru significantly enhanced the catalytic activity, demonstrating a 93 % methane conversion with raw feed and stable activity over a 100-h extended activity analysis. The catalyst characterization showed that Mg concentration increased basic sites over Mg-Al support. Due to the separation of crystalline phases as MgO-MgAl2O4, CoMg40Al had the most basic sites but poor DRM reaction performance. Balanced acidic/basic properties and well-dispersed Co-Rh nanoclusters-maintained DRM activity and stability. Ru-promoted CoMg20Al catalyzed the lowest activation energies.