Tuning hydrogenation chemistry of Pd-based heterogeneous catalysts by introducing homogeneous-like ligands

• Published in: Nature communications 2023-07, Vol.14 (1), p.3944-3944, Article 3944
• Main Authors: Zhang, Jianghao, Hu, Wenda, Qian, Binbin, Li, Houqian, Sudduth, Berlin, Engelhard, Mark, Zhang, Lian, Hu, Jianzhi, Sun, Junming, Zhang, Changbin, He, Hong, Wang, Yong
• Format: Article
• Language: English
• Subjects: 140/131; 140/146; 147/137; 147/143; 639/638/77/884; 639/638/77/885; 639/638/77/887; Acetylene; Catalysts; Chemical synthesis; Cleavage; Diphenyl ether; Electrons; Ethene; Ethylene; Humanities and Social Sciences; Hydrogenation; Hydrogenolysis; Ligands; Metals; multidisciplinary; Noble metals; Organometallic compounds; Science; Science (multidisciplinary); Selectivity; Side reactions
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-39478-2

Noble metals have been extensively employed in a variety of hydrotreating catalyst systems for their featured functionality of hydrogen activation but may also bring side reactions such as undesired deep hydrogenation. It is crucial to develop a viable approach to selectively inhibit side reactions while preserving beneficial functionalities. Herein, we present modifying Pd with alkenyl-type ligands that forms homogeneous-like Pd-alkene metallacycle structure on the heterogeneous Pd catalyst to achieve the selective hydrogenolysis and hydrogenation. Particularly, a doped alkenyl-type carbon ligand on Pd-Fe catalyst is demonstrated to donate electrons to Pd, creating an electron-rich environment that elongates the distance and weakens the electronic interaction between Pd and unsaturated C of the reactants/products to control the hydrogenation chemistry. Moreover, high H 2 activation capability is maintained over Pd and the activated H is transferred to Fe to facilitate C-O bond cleavage or directly participate in the reaction on Pd. The modified Pd-Fe catalyst displays comparable C-O bond cleavage rate but much higher selectivity (>90%) than the bare Pd-Fe (90%) in acetylene hydrogenation. This work sheds light on the controlled synthesis of selective hydrotreating catalysts via mimicking homogeneous analogues. Noble metals have been extensively employed in a variety of hydrotreating catalyst systems. Here, the authors demonstrate that coordinating Pd with alkenyl-type ligands creates an electron-rich environment for Pd entity to weaken the interaction between Pd and unsaturated C for selective hydrogenation.