The Immobilization of Pd(II) on Porous Organic Polymers for Semihydrogenation of Terminal Alkynes

作者：Jianguo Liu, Nan Wang, Jianan Liu, Ming Li, Ying Xu, Chenguang Wang, Yanzhi Wang, Haoquan Zheng, Longlong Ma · 发表于：ACS Applied Materials & Interfaces · 年份：2020 · DOI：10.1021/acsami.0c14486 · 被引用次数：18 · 研究领域：Covalent Organic Framework Applications、Metal-Organic Frameworks: Synthesis and Applications、Advanced Photocatalysis Techniques

Highly selective catalytic hydrogenation of alkynes to alkenes is a highly important reaction owing to its industrial and commercial application. Specifically, semihydrogenation of terminal alkynes has been more challenging than internal alkenes even using Lindlar catalysts. Also, the high reduction degree state metal-supported catalysts like Pd 0 /C, Pt 0 /C, and Ru 0 /C have been well-known to be used widely in hydrogenation due to their super activity. However, charcoal can absorb a large amount of water; Pd/C with 50% water is convenient on a large-scale synthesis. Charcoal generally bears oxygen groups on its surface, which are responsible for low selectivity and undesired products. Even typically, only 10–60% of the Pd metal atoms are exposed, they still suffer from poor stability in acids owing to leaching. Herein, we intend to design active and stable metal catalysts with features as the following to avoid leaching: having strong interaction with the support and coordinatively unsaturated metal sites or low valence state metals physically isolated from the acid environment. Herein, a highly efficient semihydrogenation of terminal alkynes to produce alkenes has been realized using a heterogeneous Pd(II)/POP-GIEC catalyst, imine-linked, crystalline, and porous organic polymer supporter modified by coordination of Pd(OAc) 2 to its walls under mild conditions. Surprisingly, for the first time, modified POP-supported low reduction degree Pd II catalysts were synthesized ef...