Engineering the Coordination Environment of Single‐Rh‐Site with N and S Atoms for Efficient Methanol Carbonylation

Abstract

The local coordination environment of central active sites plays a critical role in tuning the catalytic properties of heterogeneous single‐metal‐site catalysts (HSMSCs). However, carbon supports with inert surface properties provide weak interaction with the active sites, which hamper the effective modulation of the coordination structure of HSMSCs. Herein, this work shows that introducing N and S atoms into carbon support can modify the coordination environment of single‐Rh‐site and effectively improves the catalytic activity for the methanol carbonylation reaction. The synthesized Rh/AC‐NS with single‐Rh‐site exhibits a high methanol conversion of 88% and a stable acetyl production rate of 2812 h−1, in contrast with 1285 h−1 of Rh/AC without N‐ and S‐ functional groups, and meanwhile remarkably higher than those of Rh/AC‐N and Rh/AC‐S with only N‐ or S‐ functional group under the same mild reaction conditions. As revealed by the experimental result and density functional theory (DFT) calculations, the special combination of N‐ and S‐ functional groups offers favorable coordination configuration and also beneficial electronic structure for facilitated CH3I oxidative addition and CO insertion steps of single‐Rh‐site. This work offers new opportunities for rationally tuning the coordination structure of HSMSCs for heterogeneous catalysis.