华中科技大学Qing Li小组取得一项新突破。他们的最新研究通过构建梯度轨道耦合，以诱导铂-碳化物电催化剂中的金属-载体反应，以实现高效甲醇氧化。相关论文于2024年6月21日发表在《美国化学会杂志》上。

反应性金属-载体相互作用(RMSI)是一种新兴的调节负载型金属催化剂催化性能的方法。然而，热还原对RMSI的诱导往往伴随着对金属的包封效应，这限制了RMSI的机理研究和应用。在本工作中，研究者成功地开发了一种梯度轨道耦合构建策略，在没有还原剂的情况下，在铂-碳化物体系中诱导RMSI，从而形成L1₂-Pt_xM-MC_y (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo和W)金属间电催化剂。密度泛函理论(DFT)计算表明，d(M)-2p(C)-5d(Pt)轨道的梯度耦合将诱导电子从M到C的共价键转移到Pt NPs上，从而促进了C空位(Cv)的形成和随后的M迁移(RMSI的发生)。

此外，Pt-MCx体系中Cv的形成能与RMSI的起始温度之间具有良好的相关性，证明了非金属原子空位的形成在诱发RMSI中起着关键作用。所研制的L1₂-Pt₃Ti-TiC催化剂具有优异的酸性甲醇氧化反应活性，在半电池中质量活性为2.36 A mg_Pt^-1，在直接甲醇燃料电池中峰值功率密度为187.9 mW mg_Pt^-1，是目前报道的最佳催化剂之一。

DFT计算表明，与Pt-TiC相比，L1₂-Pt₃Ti-TiC有利于减弱*CO的吸收，这是由于吸收部位从Pt转变为Ti，这是甲醇氧化增强的原因。

附：英文原文

Title: Constructing Gradient Orbital Coupling to Induce Reactive Metal–Support Interaction in Pt-Carbide Electrocatalysts for Efficient Methanol Oxidation

Author: Shenzhou Li, Gang Wang, Houfu Lv, Zijie Lin, Jiashun Liang, Xuan Liu, Yang-Gang Wang, Yunhui Huang, Guoxiong Wang, Qing Li

Issue&Volume: June 21, 2024

Abstract: Reactive metal–support interaction (RMSI) is an emerging way to regulate the catalytic performance for supported metal catalysts. However, the induction of RMSI by the thermal reduction is often accompanied by the encapsulation effect on metals, which limits the mechanism research and applications of RMSI. In this work, a gradient orbital coupling construction strategy was successfully developed to induce RMSI in Pt-carbide system without a reductant, leading to the formation of L12-PtxM-MCy (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W) intermetallic electrocatalysts. Density functional theory (DFT) calculations suggest that the gradient coupling of the d(M)-2p(C)-5d(Pt) orbital would induce the electron transfer from M to C covalent bonds to Pt NPs, which facilitates the formation of C vacancy (Cv) and the subsequent M migration (occurrence of RMSI). Moreover, the good correlation between the formation energy of Cv and the onset temperature of RMSI in Pt-MCx systems proves the key role of nonmetallic atomic vacancy formation for inducing RMSI. The developed L12-Pt3Ti-TiC catalyst exhibits excellent acidic methanol oxidation reaction activity, with mass activity of 2.36 A mgPt–1 in half-cell and a peak power density of 187.9 mW mgPt–1 in a direct methanol fuel cell, which is one of the best catalysts ever reported. DFT calculations reveal that L12-Pt3Ti-TiC favorably weakens *CO absorption compared to Pt-TiC due to the change of the absorption site from Pt to Ti, which accounts for the enhanced MOR performance.

DOI: 10.1021/jacs.4c00618

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c00618