Aniline-Based Hyper-Cross-Linked Polymer–In₂O₃ Composite Boosting CO₂ Epoxide Ring-Opening Reaction Activity without Cocatalysts

Significant efforts have been devoted to develop an efficient catalytic system without the use of cocatalysts for the conversion of CO2 to cyclocarbonate. However, the low CO2 adsorption on the surfaces of catalysts is generally attributed to their low specific surface area and thermodynamic stability. Herein, we report on the efficacy of a composite heterogeneous catalyst prepared by coating the In2O3 surface with aniline-based polymers and subsequent coordination with hydrogen-bond donating functional groups (HBD). This composite shows high catalytic performance for CO2 epoxide ring-opening reactions (99%) and excellent recycling performance (sixth run) under mild conditions without the need for cocatalysts. In contrast, the catalytic performance of In2O3 without a polymer coating is significantly reduced. This study presents a feasible strategy on building HBD sites into CO2-adsorptive polymer-coated In2O3 surface and realizing CO2 cycloaddition reaction in an aerobic environment.