Copper Single Atom-Triggered Niobia–Ceria Catalyst for Efficient Low-Temperature Reduction of Nitrogen Oxides
Shaohua Xie, Wei Tan, Yuejin Li, Lu Ma, Steven N. Ehrlich, Jiguang Deng, Peng Xu, Fei Gao, Lin Dong, Fudong Liu
Abstract
To reduce nitrogen oxide (NOx) emission from diesel engines in the cold-start process benefitting the atmospheric environment, catalysts with superior low-temperature NOx removal efficiency are highly demanded. Herein, we report an efficient Nb2O5/CuO/CeO2 (NbCuCe) oxide catalyst for the selective catalytic reduction (SCR) of NOx, showing much higher DeNOx activity below 200 °C, superior sulfur resistance, faster response, and much less NH3 slip than the state-of-the-art Cu-CHA zeolite catalyst. Atomically dispersed Cu species facilitate the strong interaction between Cu and the Nb/Ce base catalyst, which significantly improves the low-temperature redox properties at Cu–O–Ce sites and NH3 adsorption/activation at Nb–O–Cu sites, thus contributing to the superior SCR performance of NbCuCe at low temperatures. The developed NbCuCe catalyst is highly promising for efficient DeNOx from cold-start diesel engines and can be coupled with Cu-CHA to achieve a broad operation temperature window.