2025年4月15日，清华大学章名田课题组在《美国化学会杂志》发表论文，他们发现了氧还原中的双金属协同作用：量身定制的金属-金属相互作用如何增强协同催化作用。

以细胞色素c氧化酶和多铜氧化酶为灵感的双金属协同催化在其电子氧还原催化剂的发展中起着至关重要的作用。金属间距离是影响协同效应的关键因素，但其对选择性氧还原催化中双金属协同性的确切影响还有待深入研究。

研究组采用一系列具有不同连接的铜配合物来系统地调节电催化氧还原中的Cu···Cu距离。结构-活性关系分析表明，在pH 7.0的水溶液中，双Cu中心较短的催化剂的电子选择性（BPMPDCu₂和BPMANCu₂的电子选择性接近100%）明显高于距离较长的催化剂（6-HPACu₂的电子选择性低于80%）。值得注意的是，BPMPDCu₂的催化活性分别比6-HPACu₂和BPMANCu₂快11倍和237倍，这与它们的Cu···Cu距离没有直接关系。

对低价LCu^I₂中间体的进一步研究，在DFT计算的支持下，表明氧结合过程是电催化条件下的速率决定步骤，并且对Cu^I··Cu^I距离敏感。最近的具有强Cu^I··Cu^I相互作用特征的BPMANCu^I₂和更远的具有分离铜位点的6-HPACu^I₂都阻碍了有效的O₂结合。相比之下，BPMANCu^I₂保持最佳的Cu···Cu距离，有利于O₂结合，并确保在整个催化循环中保持良好的双金属协同性。这项工作强调了金属-金属距离调节在双金属协同选择性氧还原中的重要意义，为合理设计高性能氧还原催化剂提供了有价值的见解。

附：英文原文

Title: Bimetallic Synergy in Oxygen Reduction: How Tailored Metal–Metal Interactions Amplify Cooperative Catalysis

Author: Qi-Fa Chen, Yao Xiao, Kai Hua, Hong-Tao Zhang, Ming-Tian Zhang

Issue&Volume: April 15, 2025

Abstract: Bimetallic cooperative catalysis, inspired by cytochrome c oxidase and multicopper oxidase, plays a crucial role in the development of four-electron oxygen reduction catalysts. The distance between metals is a crucial factor affecting the cooperative effect, but its precise influence on bimetallic cooperativity in selective oxygen reduction catalysis still awaits an in-depth understanding. Herein, we employ a series of dicopper complexes with varying linkers to systematically adjust the Cu···Cu distance for electrocatalytic oxygen reduction. Structure–activity relationship analyses reveal that catalysts with a shorter dicopper center exhibited significantly higher four-electron selectivity (approaching 100% for BPMPDCu2 and BPMANCu2) than that with a longer distance (below 80% for 6-HPACu2) in an aqueous solution (pH 7.0). Notably, the catalytic activity of BPMPDCu2 is 11 times and 237 times faster than those of 6-HPACu2 and BPMANCu2, respectively, which does not correlate directly with their Cu···Cu distances. Further investigations into low-valent LCuI2 intermediates, supported by DFT calculations, indicate that the oxygen binding process is the rate-determining step under electrocatalytic conditions and is sensitive to the CuI···CuI distance. The closest BPMANCuI2 characterized by strong CuI–CuI interactions and the more distant 6-HPACuI2 with its separated dicopper sites both hinder effective O2 binding. In contrast, BPMPDCuI2 maintains an optimal Cu···Cu distance that facilitates O2 binding and ensures robust bimetallic cooperativity throughout the catalytic cycle. This work underscores the significance of metal–metal distance regulation in bimetallic cooperatively selective oxygen reduction and provides valuable insights for the rational design of high-performance oxygen reduction catalysts.

DOI: 10.1021/jacs.5c01406

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c01406