Isolating Contiguous Ir Atoms and Forming Ir–W Intermetallics with Negatively Charged Ir for Efficient NO Reduction by CO. Issue 49 (31st October 2022)

• Record Type: Journal Article
• Authors: Ji, Yongjun; Liu, Shaomian; Zhu, Hongdan; Xu, Wenqing; Jiang, Ruihuan; Zhang, Yu; Yu, Jian; Chen, Wenxing; Jia, Lihua; Jiang, Jingang; Zhu, Tingyu; Zhong, Ziyi; Wang, Dingsheng; Xu, Guangwen; Su, Fabing
• Is Part Of: Advanced materials. Volume 34:Issue 49(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-31
• Subjects: CO+NO -- intermetallic compounds -- Ir single atoms -- O 2 resistance -- SO 2 resistance; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202205703
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: The lack of efficient catalysts with a wide working temperature window and vital O2 and SO2 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 SiO2 (KIT‐6). Notably, this catalyst enables complete NO conversion to N2 at 250 °C in the presence of 1% O2 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 SO2 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 N2 O and NO2 intermediates by CO. Abstract : A novel Ir‐based catalyst (IrW‐WO3 /KIT‐6) containing only 1 wt% Ir is synthesized for efficient catalytic reduction of NO by CO to N2 under O2 ‐containing conditions. This catalyst consists of ordered mesoporous SiO2 (KIT‐6) supported with WO3 nanoparticles, and the latter is covered with atomic‐dispersed IrW intermetallics.