Yin Yong, Luo Bingcheng, Li Kezhi, Moskowitz Benjamin M, Mosevitzky Lis Bar, Wachs Israel E, Zhu Minghui, Sun Ye, Zhu Tianle, Li Xiang
School of Space and Environment, Beihang University, Beijing, 100191, China.
College of Science, China Agricultural University, Beijing, 100083, China.
Nat Commun. 2024 Apr 27;15(1):3592. doi: 10.1038/s41467-024-47878-1.
Supported nanoclusters (SNCs) with distinct geometric and electronic structures have garnered significant attention in the field of heterogeneous catalysis. However, their directed synthesis remains a challenge due to limited efficient approaches. This study presents a plasma-assisted treatment strategy to achieve supported metal oxide nanoclusters from a rapid transformation of monomeric dispersed metal oxides. As a case study, oligomeric vanadia-dominated surface sites were derived from the classic supported VO-WO/TiO (VWT) catalyst and showed nearly an order of magnitude increase in turnover frequency (TOF) value via an H-plasma treatment for selective catalytic reduction of NO with NH. Such oligomeric surface VO sites were not only successfully observed and firstly distinguished from WO and TiO by advanced electron microscopy, but also facilitated the generation of surface amide and nitrates intermediates that enable barrier-less steps in the SCR reaction as observed by modulation excitation spectroscopy technologies and predicted DFT calculations.
具有独特几何和电子结构的负载型纳米团簇(SNCs)在多相催化领域引起了广泛关注。然而,由于有效方法有限,其定向合成仍然是一个挑战。本研究提出了一种等离子体辅助处理策略,通过单体分散金属氧化物的快速转变来制备负载型金属氧化物纳米团簇。作为一个案例研究,从经典的负载型VO-WO/TiO(VWT)催化剂中衍生出以低聚钒酸盐为主的表面位点,通过H等离子体处理用于NH选择性催化还原NO,其周转频率(TOF)值提高了近一个数量级。这种低聚表面VO位点不仅通过先进的电子显微镜成功观察到并首次与WO和TiO区分开来,而且通过调制激发光谱技术观察到并经DFT计算预测,促进了表面酰胺和硝酸盐中间体的生成,这些中间体在SCR反应中实现了无势垒步骤。