Catalytic cooperation between Ru and Pd atoms on hierarchical porous Ce-based oxide for boosting engine exhaust purification.

Xu, Linsheng; Qin, Tian; Li, Yuanfeng; Guo, Hao; Hu, Qiao; Xiong, Jing; Ma, Yaxiao; Zhang, Peng et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Simultaneous oxidation of soot and CH<sub>4</sub> emitted from natural gas-diesel dual fuel engine is a new challenge. Herein, a robust catalyst of binary Ru-Pd components supported on three-dimensional ordered macro-mesoporous cerium-zirconium oxide (RuPd/3DOMM-CZO) is elaborately constructed. Ordered macro-mesopore structure in novel hierarchical porous cerium-zirconium oxide can respectively enhance mass transfer of soot and gaseous reactants, and binary Ru-Pd active components can improve activation for NO and CH<sub>4</sub>. RuPd/3DOMM-CZO catalyst exhibits excellent catalytic performance and stability during simultaneous soot and CH<sub>4</sub> oxidation. Based on the results of characterizations and theoretical calculations, Ru site in binary Ru-Pd components is responsible for catalyzing NO oxidation to NO<sub>2</sub>, which is key step of NO<sub>x</sub>-assisted soot oxidation mechanism, while Pd site can activate the C-H bond of CH<sub>4</sub> for boosting oxidation to CO<sub>2</sub>; the catalytic cooperation between Ru and Pd atoms can promote the rate-determining step to realize simultaneous oxidation of soot and CH<sub>4</sub>.