Enhanced CO2 utilization via methane tri-reforming over Ru incorporated Co/MgO-Al2O3 catalyst: Influence of La and Ce promoters

The catalytic efficiency of Ru incorporated Co-based catalysts supported on cylindrical extrudates of MgO-Al2O3 mixed oxide with promoters La and Ce were investigated for syngas production by methane tri reforming for the effective utilization of CO2 present in varied sources, including industrial waste flue gases. Ru was chosen as one of the active metal due to its characteristic hydrogen spillover phenomena and high coke resistivity. Moreover, Co and Ru coexistence plays a pivotal role in enhanced reactants' conversion and catalyst stability via the bimetallic synergy. The activity study revealed that Co content, Co-Ru synergy and La, Ce-doping influenced the catalytic activity as the prepared catalysts evaluated at different operating conditions like temperature 600-800 degrees C, pressure 1 atm and GHSV 4000-10,000 ml g(cat)(-1) (h)-1 under an optimized molar feed ratio of CH4:CO2: H2O:O-2 = 1:0.75:0.75:0.1. The variation in feed composition was also tested over the Co-Ru catalyst and obtained a product syngas ratio 1-2. The other key factors that influenced the catalytic performance were Co crystallite size, Co3O4 reducibility, surface basicity and metal-support interface as observed from the stability studies and detailed physicochemical characterization of fresh and spent catalysts using N-2 physisorption, XRD, H-2-TPR, CO2-TPD, SEM, TEM, XPS, and TG-DTG. Further, the addition of La facilitated the formation of a large number of surface basic sites than Ce via better La-(Co-Ru)-support interface resulted in superior coke resistivity for the La-doped Co-Ru catalyst with high conversions of CH4 and CO2 during 100 h time on stream study.

Automated summary

The catalytic efficiency of Ru incorporated Co-based catalysts supported on MgO-Al2O3 mixed oxide with La and Ce promoters was studied for syngas production by methane tri reforming, aiming to effectively utilize CO2 from various sources. The coexistence of Co and Ru enhanced reactants' conversion and catalyst stability through bimetallic synergy. The addition of La facilitated a better La-(Co-Ru)-support interface, resulting in superior coke resistivity and high conversions of CH4 and CO2 during a 100-hour time on stream study.