Fabrication of Highly Dispersed Ru Catalysts on CeO<sub>2</sub> for Efficient C<sub>3</sub>H<sub>6</sub> Oxidation
Bifeng Zhang, Jiawei Yang, Yibo Mu, Xiaoyu Ji, Yandi Cai, Nan Jiang, Shaohua Xie, Qiuhui Qian, Fudong Liu, Wei Tan, Lin Dong
Abstract
Emissions of volatile organic compounds (VOCs) threaten both the environment and human health. To realize the elimination of VOCs, Ru/CeO 2 catalysts 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/CeO 2 catalysts 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-CeO 2 -BTC) and conventional incipient wetness impregnation method (Ru/CeO 2 -BTC), respectively. In a typical model reaction of C 3 H 6 oxidation, atomically dispersed Ru δ+ species with the formation of abundant Ru–O–Ce linkages on Ru-CeO 2 -BTC were found to perform much better than agglomerated RuO x species on Ru/CeO 2 -BTC. Further characterizations and mechanism study disclosed that Ru-CeO 2 -BTC catalyst with atomically dispersed Ru ions and more superior low temperature redox performance compared to Ru/CeO 2 -BTC could better facilitate the adsorption/activation of C 3 H 6 and the decomposition/desorption of intermediates, thus exhibiting superior C 3 H 6 oxidation activity. This work elucidated the reactive sites on Ru/CeO 2 catalysts in the C 3 H 6 oxidation reaction and provided insightful guidance for designing efficient Ru/CeO 2 catalysts to eliminate VOCs.