Jiang Kunhong, Jiang Yong, Liang Zhong, Zhang Wenshuo, Liu Hengjun, Shi Jiali, Wang Siyuan, Zhong Ziyun, Du Yaping
Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, P. R. China.
Mater Horiz. 2025 Oct 27;12(21):9094-9105. doi: 10.1039/d5mh01041a.
The semi-hydrogenation of ethynylbenzene is a fundamental reaction in the synthesis of polymer precursors. However, achieving a balance between catalytic activity and styrene selectivity remains a significant challenge due to the risk of over-hydrogenation. Herein, we design ternary PtCoCe rare earth alloys to synergistically regulate electronic states and adsorption geometries, thereby enhancing selective hydrogenation. The optimized PtCoCe catalyst exhibits remarkable performance, achieving 98.3% conversion of ethynylbenzene, 85.1% selectivity for styrene, and a turnover frequency (TOF) of 1549.6 h under mild conditions, surpassing most reported Pt-based catalysts. spectroscopy, combined with kinetic analysis, demonstrates that the catalyst facilitates the adsorption and conversion of ethynylbenzene. Density functional theory (DFT) calculations reveal that directional electron transfer from Ce (4f) to Pt/Co (5d) d-f orbital coupling effectively modulates the position of the Pt d-band center, weakening the over-adsorption of the intermediate styrene while preserving optimal activation of ethynylbenzene. Additionally, the large ionic radius of Ce spatially alters the adsorption configuration of styrene, reducing its adsorption energy and increasing the energy barrier to suppress ethylbenzene formation. This study illustrates that rare earth alloy engineering is a universal strategy to address the activity-selectivity trade-off in heterogeneous catalysis.
乙炔基苯的半氢化反应是聚合物前体合成中的一个基本反应。然而，由于存在过度氢化的风险，在催化活性和苯乙烯选择性之间取得平衡仍然是一个重大挑战。在此，我们设计了三元PtCoCe稀土合金，以协同调节电子态和吸附几何结构，从而增强选择性氢化。优化后的PtCoCe催化剂表现出卓越的性能，在温和条件下乙炔基苯的转化率达到98.3%，苯乙烯选择性为85.1%，周转频率（TOF）为1549.6 h⁻¹，超过了大多数已报道的Pt基催化剂。光谱学结合动力学分析表明，该催化剂促进了乙炔基苯的吸附和转化。密度泛函理论（DFT）计算表明，从Ce（4f）到Pt/Co（5d）的定向电子转移以及d-f轨道耦合有效地调节了Pt d带中心的位置，在保持乙炔基苯最佳活化的同时削弱了中间体苯乙烯的过度吸附。此外，Ce的大离子半径在空间上改变了苯乙烯的吸附构型，降低了其吸附能并增加了抑制乙苯形成的能垒。这项研究表明，稀土合金工程是解决多相催化中活性-选择性权衡问题的通用策略。
