Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467.
Department of Physics and Astronomy, University of California-Irvine, Irvine, CA 92697.
Proc Natl Acad Sci U S A. 2023 Jan 3;120(1):e2206850120. doi: 10.1073/pnas.2206850120. Epub 2022 Dec 28.
Atomically dispersed catalysts have been shown highly active for preferential oxidation of carbon monoxide in the presence of excess hydrogen (PROX). However, their stability has been less than ideal. We show here that the introduction of a structural component to minimize diffusion of the active metal center can greatly improve the stability without compromising the activity. Using an Ir dinuclear heterogeneous catalyst (DHC) as a study platform, we identify two types of oxygen species, interfacial and bridge, that work in concert to enable both activity and stability. The work sheds important light on the synergistic effect between the active metal center and the supporting substrate and may find broad applications for the use of atomically dispersed catalysts.
原子分散催化剂在存在过量氢气的情况下（PROX）对一氧化碳的优先氧化表现出很高的活性。然而，它们的稳定性并不理想。我们在这里表明，引入结构组件以最小化活性金属中心的扩散，可以在不影响活性的情况下大大提高稳定性。使用双核铱均相催化剂（DHC）作为研究平台，我们确定了两种协同作用的氧物种，即界面氧和桥氧，它们既能提高活性，又能提高稳定性。这项工作为活性金属中心和支撑基底之间的协同效应提供了重要的启示，并可能为原子分散催化剂的应用提供广泛的应用。
