Key Laboratory of Applied Chemistry of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310036, China.
Molecules. 2023 Mar 3;28(5):2335. doi: 10.3390/molecules28052335.
The rational regulation of catalyst active sites at atomic scale is a key approach to unveil the relationship between structure and catalytic performance. Herein, we reported a strategy for the controllable deposition of Bi on Pd nanocubes (Pd NCs) in the priority order from corners to edges and then to facets (Pd NCs@Bi). The spherical aberration-corrected scanning transmission electron microscopy (ac-STEM) results indicated that BiO with an amorphous structure covers the specific sites of Pd NCs. When only the corners and edges of the Pd NCs were covered, the supported Pd NCs@Bi catalyst exhibited an optimal trade-off between high conversion and selectivity in the hydrogenation of acetylene to ethylene under ethylene-rich conditions (99.7% CH conversion and 94.3% CH selectivity at 170 °C) with remarkable long-term stability. According to the H-TPR and CH-TPD measurements, the moderate hydrogen dissociation and the weak ethylene adsorption are responsible for this excellent catalytic performance. Following these results, the selectively Bi-deposited Pd nanoparticle catalysts showed incredible acetylene hydrogenation performance, which provides a feasible perspective to design and develop highly selective hydrogenation catalysts for industrial applications.
在原子尺度上合理调控催化剂活性位是揭示结构与催化性能之间关系的关键途径。在此，我们报道了一种在 Pd 纳米立方体（Pd NCs）上可控沉积 Bi 的策略，Bi 的沉积优先从角到边再到面（Pd NCs@Bi）。球差校正扫描透射电子显微镜（ac-STEM）结果表明，具有非晶结构的 BiO 覆盖了 Pd NCs 的特定位置。当仅 Pd NCs 的角和边被覆盖时，负载的 Pd NCs@Bi 催化剂在富乙烯条件下（170°C 时 CH 转化率为 99.7%，CH 选择性为 94.3%），在乙炔氢化为乙烯的反应中表现出高转化率和选择性之间的最佳权衡，具有显著的长期稳定性。根据 H-TPR 和 CH-TPD 测量结果，适度的氢解离和较弱的乙烯吸附是这种优异催化性能的原因。根据这些结果，选择性沉积 Bi 的 Pd 纳米颗粒催化剂表现出令人难以置信的乙炔加氢性能，为设计和开发用于工业应用的高选择性加氢催化剂提供了可行的视角。
