Fabrication of Highly Dispersed Ru Catalysts on CeO2for Efficient C3H6Oxidation

Emissions of volatile organic compounds (VOCs) threaten both the environment and human health. To realize the elimination of VOCs, Ru/CeO2catalysts have been intensively investigated and applied. Although it has been widely acknowledged that the catalytic performance of platinum group metal catalysts was highly determined by their dispersion and coordination environment, the most reactive structures on Ru/CeO2catalysts for VOCs oxidation are still ambiguous. In this work, starting from Ce-BTC (BTC = 1,3,5-benzenetricarboxylic acid) materials, atomically dispersed Ru catalysts and agglomerated Ru catalysts were successfully created via one-step hydrothermal method (Ru-CeO2-BTC) and conventional incipient wetness impregnation method (Ru/CeO2-BTC), respectively. In a typical model reaction of C3H6oxidation, atomically dispersed Ruδ+species with the formation of abundant Ru–O–Ce linkages on Ru-CeO2-BTC were found to perform much better than agglomerated RuOxspecies on Ru/CeO2-BTC. Further characterizations and mechanism study disclosed that Ru-CeO2-BTC catalyst with atomically dispersed Ru ions and more superior low temperature redox performance compared to Ru/CeO2-BTC could better facilitate the adsorption/activation of C3H6and the decomposition/desorption of intermediates, thus exhibiting superior C3H6oxidation activity. This work elucidated the reactive sites on Ru/CeO2catalysts in the C3H6oxidation reaction and provided insightful guidance for designing efficient Ru/CeO2catalysts to eliminate VOCs.