Dual-Ionically Bound Single-Site Rhodium on Porous Ionic Polymer Rivals Commercial Methanol Carbonylation Catalysts

Abstract

Novel porous polymers can serve as self-supporting solid carriers and provide abundant coordination or charged sites for single-site metals, and thus are emerging as advanced functional materials in heterogeneous catalysis for various transformations traditionally catalyzed by homogeneous systems. A brief overview of the development of this heterogenization given, including the recent advances regarding electrovalent bonds by employing charged supports represented by porous ionic polymers (PIPs), which is exemplified herein with a novel single-site Rh₁ /PIP catalyst, featuring a new active site [Rh(CO)I₃ ]^2- dual-ionically bound onto a quaternary phosphonium cationic framework polymer, different from the single-ionically bound [Rh(CO)₂ I₂ ]^- in previous studies. Such a unique metal configuration of Rh₁ /PIP leads to excellent performance in vapor-phase methanol carbonylation, outperforming commercial homo- and heterogeneous catalysts.

Keywords: dual-ionic bound; heterogeneous catalysis; methanol carbonylation; porous ionic polymers; single-site Rh.