Abstract A single-Rh-site catalyst (Rh-TPISP) that was ionically-embedded on a P(V) quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation. The [Rh(CO)I3]2– unit was proposed to be the active center of Rh-TPISP for the carbonylation reaction based on detailed Rh L3-edge X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), and Rh extended X-ray absorption fine structure (EXAFS) analyses. As the highlight of this study, Rh-TPISP displayed distinctly higher activity for heterogeneous ethanol carbonylation than the reported catalytic systems in which [Rh(CO)2I2]− is the traditional active center. A TOF of 350 h−1 was obtained for the reaction over [Rh(CO)I3]2–, with >95% propionyl selectivity at 3.5 MPa and 468 K. No deactivation was detected during a near 1000 h running test. The more electron-rich Rh center was thought to be crucial for explaining the superior activity and selectivity of Rh-TPISP, and the formation of two ionic bonds between [Rh(CO)I3]2– and the cationic P(V) framework ([P]+) of the polymer was suggested to play a key role in firmly immobilizing the active species to prevent Rh leaching.

中文翻译：

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季鏻聚合物负载的双离子键 [Rh(CO)I3]2– 多相乙醇羰基化催化剂

摘要 评价了离子嵌入 P(V) 季鏻多孔聚合物上的单 Rh 位点催化剂 (Rh-TPISP)​​ 的多相乙醇羰基化反应。基于详细的Rh L3-edge X射线吸收近边结构（XANES）、X射线光电子能谱，[Rh(CO)I3]2-单元被提议作为Rh-TPISP的活性中心，用于羰基化反应。 XPS) 和 Rh 扩展 X 射线吸收精细结构 (EXAFS) 分析。作为本研究的亮点，Rh-TPISP 对多相乙醇羰基化的活性明显高于报道的催化系统，其中 [Rh(CO)2I2]- 是传统的活性中心。在 [Rh(CO)I3]2– 上的反应获得了 350 h-1 的 TOF，在 3.5 MPa 和 468 K 下丙酰选择性> 95%。在近 1000 小时的运行测试中未检测到失活。