德国杜伊斯堡大学化学系的Kai S. Exner课题组取得一项新突破。他们观察到MXenes在阳极极化条件下自发形成活性和选择性单原子中心。相关论文于2024年12月16日发表在《美国化学会杂志》上。

研究人员表示，单原子催化剂（SACs）是一种新型的活性和选择性催化剂。这些材料通常是基于锚定一种贵的过渡金属到某种载体。

在目前的工作中，研究小组将所施加的电极电位作为探针，形成类似单原子催化剂（SAC）样结构的催化活性表面位点，证明了MXenes——用于能量储存和转换的二维材料——在阳极极化条件下自发形成SAC样位点。

结合从头算分子动力学模拟和密度泛函理论框架下的电子结构计算，该团队证明了只有SAC类位点而不是MXenes的基面，分别对析氧反应和析氯反应具有高活性和选择性。

他们的发现可能简化了形成活性和选择性类SAC位点的合成途径，并可能通过将自然界的基本原理纳入材料发现中，为智能材料的发展铺平道路——当材料的原始形式是非活性的时，电极电位的应用通过形成活性和选择性单原子中心激活材料。

附：英文原文

Title: MXenes Spontaneously Form Active and Selective Single-Atom Centers under Anodic Polarization Conditions

Author: Samad Razzaq, Shohreh Faridi, Stephane Kenmoe, Muhammad Usama, Diwakar Singh, Ling Meng, Francesc Vines, Francesc Illas, Kai S. Exner

Issue&Volume: December 16, 2024

Abstract: Single-atom catalysts (SACs) have emerged as a new class of materials for the development of active and selective catalysts. These materials are commonly based on anchoring a noble transition metal to some kind of carrier. In the present work, we demonstrate that MXenes─two-dimensional materials with application in energy storage and conversion─spontaneously form SAC-like sites under anodic polarization conditions, using the applied electrode potential as a probe to form catalytically active surface sites reminiscent of a SAC-like structure. Combining ab initio molecular dynamics simulations and electronic structure calculations in the density functional theory framework, we demonstrate that only the SAC-like sites rather than the basal planes of MXenes are highly active and selective for the oxygen evolution or chlorine evolution reactions, respectively. Our findings may simplify synthetic routes toward the formation of active and selective SAC-like sites and could pave the way for the development of smart materials by incorporating fundamental principles from nature into material discovery: while the pristine form of the material is inactive, the application of an electrode potential activates the material by the formation of active and selective single-atom centers.

DOI: 10.1021/jacs.4c08518

Source: https://pubs.acs.org/doi/full/10.1021/jacs.4c08518