Zhao Liang, Akdim Ouardia, Huang Xiaoyang, Wang Kai, Douthwaite Mark, Pattisson Samuel, Lewis Richard J, Lin Runjia, Yao Bingqing, Morgan David J, Shaw Greg, He Qian, Bethell Donald, McIntosh Steven, Kiely Christopher J, Hutchings Graham J
Max Planck- Cardiff Centre on the Fundamentals of Heterogeneous Catalysis FUNCAT, Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff CF10 3AT, U.K.
Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore, 119077 Singapore.
ACS Catal. 2023 Feb 10;13(5):2892-2903. doi: 10.1021/acscatal.2c06284. eCollection 2023 Mar 3.
The aerobic oxidation of alcohols and aldehydes over supported heterogeneous catalysts can be considered as comprising two complementary and linked processes: dehydrogenation and oxygen reduction. Significant rate enhancements can be observed when these processes are catalyzed by independent active sites, coupled by electron transport between the two catalysts. This effect, termed cooperative redox enhancement (CORE), could significantly influence how researchers approach catalyst design, but a greater understanding of the factors which influence it is required. Herein, we demonstrate that the Au/Pd ratio used in physical mixtures of monometallic catalysts and phase-separated Au and Pd bimetallic catalysts dramatically influences the degree to which CORE effects can promote alcohol oxidation. Perhaps more interestingly, the roles of Au and Pd in this coupled system are determined to be interchangeable. Preliminarily, we hypothesize that this is attributed to the relative rates of the coupled reactions and demonstrate how physical properties can influence this. This deeper understanding of the factors which influence CORE is an important development in bimetallic catalysis.
脱氢和氧还原。当这些过程由独立的活性位点催化，并通过两种催化剂之间的电子传输耦合时，可以观察到显著的速率增强。这种效应被称为协同氧化还原增强（CORE），它可能会显著影响研究人员进行催化剂设计的方式，但需要更深入地了解影响它的因素。在此，我们证明了单金属催化剂的物理混合物以及相分离的金钯双金属催化剂中使用的金/钯比例，会极大地影响CORE效应促进醇氧化的程度。也许更有趣的是，金和钯在这个耦合体系中的作用被确定为可以互换。初步地，我们假设这归因于耦合反应的相对速率，并展示了物理性质如何影响这一点。对影响CORE的因素的这种更深入理解是双金属催化领域的一项重要进展。
