Atomically dispersing metal atoms on supports has been emerging as an effective strategy to maximize the atom utilization of metals for catalysis. However, due to the lack of effective tools to characterize the detailed structure of metal-support interface, the chemical functions of supports in atomically dispersed metal catalysts are hardly elucidated at the molecular level. In this work, an atomically dispersed Pd₁/TiO₂ catalyst with Ti(III) vicinal to Pd is prepared and used to demonstrate the direct involvement of metal atoms on support in the catalysis of dispersed metal atoms. Systematic studies reveal that the Ti(III)-O-Pd interface facilitates the activation of O₂ into superoxide (O₂⁻), thus promoting the catalytic oxidation. The catalyst exhibits the highest CO turn-over frequency among ever-reported Pd-based catalysts, and enhanced catalysis in the combustion of harmful volatile organic compound (i.e., toluene) and green-house gas (i.e., methane). The demonstrated direct involvement of metal atoms on oxide support suggests that the real active sites of atomically dispersed metal catalysts can be far beyond isolated metal atoms themselves. Metal atoms on oxide supports in the vicinity serve as another vector to promote the catalysis of atomically dispersed metal catalysts.

将金属原子原子分散在载体上已成为最大限度地利用金属原子进行催化的有效策略。然而，由于缺乏有效的工具来表征金属-载体界面的详细结构，原子分散的金属催化剂中载体的化学功能很难在分子水平上阐明。在这项工作中，制备了一种原子分散的 Pd ₁ /TiO ₂催化剂，其中 Ti(III) 与 Pd 相邻，并用于证明金属原子在载体上直接参与分散金属原子的催化作用。系统研究表明，Ti(III)-O-Pd 界面有助于将 O ₂活化为超氧化物（O ₂ ^-), 从而促进催化氧化。该催化剂在已报道的 Pd 基催化剂中表现出最高的 CO 转换频率，并增强了对有害挥发性有机化合物（即甲苯）和温室气体（即甲烷）燃烧的催化作用。金属原子在氧化物载体上的直接参与表明，原子分散的金属催化剂的真正活性位点可能远远超出孤立的金属原子本身。附近氧化物载体上的金属原子作为另一个载体来促进原子分散的金属催化剂的催化作用。