Ge Xiaohu, Jing Yundao, Wang Wenjie, Cao Yueqiang, Zhang Jing, Qian Gang, Jiang Hao, Zhou Xinggui, Chen De, Yuan Weikang, Duan Xuezhi
State Key Laboratory of Chemical Engineering and Low-Carbon Technology, School of Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
J Am Chem Soc. 2025 Aug 20;147(33):30178-30189. doi: 10.1021/jacs.5c08564. Epub 2025 Aug 5.
Catalytic hydrogenation of trace alkynes in excess alkenes is essential for producing polymer-grade olefins from steam cracking and alkane dehydrogenation, but achieving high selectivity without sacrificing activity remains a significant challenge. Herein, we report a catalyst design that synergistically integrates computationally proposed surface PdSb trimer sites with near-surface Pd sites (Pd) on the 6/ PdSb intermetallic catalyst to achieve the semihydrogenation of alkynes with both high activity and selectivity. Alkynes can be readily activated through strong σ-bonding on the PdSb trimer sites, whereas alkenes are only weakly adsorbed via π-interactions due to their matched electronic structures and spatial configurations. Moreover, the neighboring Pd cooperates with the PdSb sites to achieve spontaneous dissociation of H for subsequent hydrogenation. Consequently, the fabricated PdSb intermetallic catalyst exhibits ethylene and propylene selectivities of 96.50% and 98.65%, respectively, at nearly complete conversions of acetylene and propyne, under industrially relevant conditions, outperforming state-of-the-art catalysts. This study demonstrates a promising strategy that synergizes near-surface and surface ensemble sites to spatially and energetically match with the target reaction pathway, enabling the overcoming of the trade-off between activity and selectivity in hydrogenation.
在由蒸汽裂解和烷烃脱氢制备聚合物级烯烃的过程中，将过量烯烃中的痕量炔烃进行催化氢化至关重要，但在不牺牲活性的情况下实现高选择性仍然是一项重大挑战。在此，我们报道了一种催化剂设计，该设计将通过计算提出的表面PdSb三聚体位点与6/PdSb金属间化合物催化剂上的近表面Pd位点（Pd）协同整合，以实现炔烃的半氢化，同时具有高活性和选择性。炔烃可通过在PdSb三聚体位点上的强σ键合轻松活化，而烯烃由于其匹配的电子结构和空间构型，仅通过π相互作用弱吸附。此外，相邻的Pd与PdSb位点协同作用，实现H的自发解离以进行后续氢化。因此，在工业相关条件下，制备的PdSb金属间化合物催化剂在乙炔和丙炔几乎完全转化时，乙烯和丙烯选择性分别为96.50%和98.65%，优于现有催化剂。这项研究展示了一种有前景的策略，即协同近表面和表面整体位点，使其在空间和能量上与目标反应路径相匹配，从而克服氢化过程中活性和选择性之间的权衡。
