Isolating Contiguous Ir Atoms and Forming Ir–W Intermetallics with Negatively Charged Ir for Efficient NO Reduction by CO
Yongjun Ji, Shaomian Liu, Hongdan Zhu, Wenqing Xu, Ruihuan Jiang, Yu Zhang, Jian Yu, Wenxing Chen, Lihua Jia, Jingang Jiang, Tingyu Zhu, Ziyi Zhong, Dingsheng Wang, Guangwen Xu, Fabing Su
Abstract
Abstract The lack of efficient catalysts with a wide working temperature window and vital O 2 and SO 2 resistance for selective catalytic reduction of NO by CO (CO‐SCR) largely hinders its implementation. Here, a novel Ir‐based catalyst with only 1 wt% Ir loading is reported for efficient CO‐SCR. In this catalyst, contiguous Ir atoms are isolated into single atoms, and Ir–W intermetallic nanoparticles are formed, which are supported on ordered mesoporous SiO 2 (KIT‐6). Notably, this catalyst enables complete NO conversion to N 2 at 250 °C in the presence of 1% O 2 and has a wide temperature window (250–400 °C), outperforming the comparison samples with Ir isolated‐single‐atomic‐sites and Ir nanoparticles, respectively. Also, it possesses a high SO 2 tolerance. Both experimental results and theoretical calculations reveal that single Ir atoms are negatively charged, dramatically enhancing the NO dissociation, while the Ir–W intermetallic nanoparticles accelerate the reduction of the N 2 O and NO 2 intermediates by CO.