Zhang Tianyu, Yang Xiang, Jin Jing, Han Xu, Fang Yingyan, Zhou Xulin, Li Yaping, Han Aijuan, Wang Yu, Liu Junfeng
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences Institution, Beijing, 100190, China.
Adv Mater. 2024 Jan;36(4):e2304144. doi: 10.1002/adma.202304144. Epub 2023 Dec 6.
Modulating the electronic metal-support interaction (EMSI) of the single-atomic sites against leaching via microenvironment regulation is critical to achieving high activity and stability but remains challenging. Herein, this work selectively confines Pt single atoms on CoFe layered double hydroxide (LDH) by three oxygen atoms around cation vacancy (Pt /LDH ) or one oxygen atom at the regular surface (Pt /LDH) via cation vacancy engineering. By characterizing the structural evolution of the obtained catalysts before and after vacancy construction and single-atom anchoring, this work demonstrates how the microenvironments modulate the EMSI and the catalytic performance. Theoretical simulations further reveal a significantly enhanced EMSI effect by the three-coordinated Pt atoms on cation vacancies in Pt /LDH , which endows a more prominent anti-leaching feature than the one-coordinated ones on the regular surface. As a result, the Pt /LDH catalyst shows exceptional performance in anti-Markovnikov alkene hydrosilylation, with a turnover frequency of 1.3 × 10 h . More importantly, the enhanced EMSI of Pt /LDH effectively prevented the leaching of Pt atom from the catalyst surface and can be recycled at least ten times with only a 3.4% loss of catalytic efficiency with minimal Pt leaching, and reach a high turnover number of 1.0 × 10 .
通过微环境调控来调节单原子位点的电子金属-载体相互作用(EMSI)以防止浸出,对于实现高活性和稳定性至关重要,但仍然具有挑战性。在此,这项工作通过阳离子空位工程,将Pt单原子选择性地限制在阳离子空位周围的三个氧原子上的CoFe层状双氢氧化物(LDH)(Pt/LDH )或规则表面上的一个氧原子上(Pt/LDH)。通过表征空位构建和单原子锚定前后所得催化剂的结构演变,这项工作展示了微环境如何调节EMSI和催化性能。理论模拟进一步揭示了Pt/LDH中阳离子空位上的三配位Pt原子显著增强了EMSI效应,这赋予了比规则表面上的单配位Pt原子更突出的抗浸出特性。结果,Pt/LDH催化剂在反马氏规则烯烃硅氢化反应中表现出优异的性能,周转频率为1.3×10 h 。更重要的是,Pt/LDH增强的EMSI有效地防止了Pt原子从催化剂表面浸出,并且可以循环至少十次,催化效率仅损失3.4%,Pt浸出极少,并且达到了1.0×10的高周转数。