Li Shenzhou, Wang Gang, Lv Houfu, Lin Zijie, Liang Jiashun, Liu Xuan, Wang Yang-Gang, Huang Yunhui, Wang Guoxiong, Li Qing
State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
J Am Chem Soc. 2024 Jul 3;146(26):17659-17668. doi: 10.1021/jacs.4c00618. Epub 2024 Jun 21.
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 L1-PtM-MC (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 (M)-2(C)-5(Pt) orbital would induce the electron transfer from M to C covalent bonds to Pt NPs, which facilitates the formation of C vacancy () and the subsequent M migration (occurrence of RMSI). Moreover, the good correlation between the formation energy of and the onset temperature of RMSI in Pt-MC systems proves the key role of nonmetallic atomic vacancy formation for inducing RMSI. The developed L1-PtTi-TiC catalyst exhibits excellent acidic methanol oxidation reaction activity, with mass activity of 2.36 A mg in half-cell and a peak power density of 187.9 mW mg in a direct methanol fuel cell, which is one of the best catalysts ever reported. DFT calculations reveal that L1-PtTi-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.
反应性金属-载体相互作用（RMSI）是一种调节负载型金属催化剂催化性能的新兴方法。然而，通过热还原诱导RMSI时，往往伴随着对金属的包裹效应，这限制了RMSI的机理研究和应用。在这项工作中，成功开发了一种梯度轨道耦合构建策略，在无还原剂的情况下在Pt-碳化物体系中诱导RMSI，从而形成L1-PtM-MC（M = Ti、Zr、Hf、V、Nb、Ta、Cr、Mo和W）金属间化合物电催化剂。密度泛函理论（DFT）计算表明，(M)-2(C)-5(Pt)轨道的梯度耦合会诱导电子从M转移至C共价键再到Pt纳米颗粒，这有利于C空位（）的形成以及随后的M迁移（RMSI的发生）。此外，Pt-MC体系中形成能与RMSI起始温度之间的良好相关性证明了非金属原子空位形成对诱导RMSI的关键作用。所开发的L1-PtTi-TiC催化剂表现出优异的酸性甲醇氧化反应活性，在半电池中的质量活性为2.36 A mg，在直接甲醇燃料电池中的峰值功率密度为187.9 mW mg，是有史以来报道的最佳催化剂之一。DFT计算表明，与Pt-TiC相比，L1-PtTi-TiC由于吸收位点从Pt变为Ti，有利于减弱*CO吸附，这解释了其增强的甲醇氧化反应性能。
