Quaternary phosphonium polymer-supported dual-ionically bound [Rh(CO)I3]2– catalyst for heterogeneous ethanol carbonylation

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