Frustrated Lewis Pair Meets Polyhedral Oligomeric Silsesquioxane: Water-Tolerant Hybrid Porous Networks for Robust, Efficient, and Recyclable CO2 Catalysis

Abstract

Frustrated Lewis pair chemistry (FLP) occupy a crucial position in nonmetal-mediated catalysis, especially toward activation of inert gas molecules. Yet, one formidable issue of homogeneous FLP catalysts is their instability on preservation and recycling. Here we contribute a general solution that marries the polyhedral oligomeric silsesquioxane (POSS) with a structurally specific frustrated Lewis acid to fabricate porous polymer networks, which can form in situ water-insensitive heterogeneous FLP catalysts upon employing Lewis base substrates. The excellent resistance to water derives from the synergy of superhydrophobicity of silsesquioxane cage and the multiscale micro/nano-structural effect of formed porous networks. Using CO₂ as a C1 feedstock, the FLP-POSS hybrid materials allow for the catalytically conversion of a variety of diamine substrates into the medicinal benzimidazole derivatives. Not only can the FLP units be immobilized on the networks meeting the needs of recyclable utilization but, more importantly, the materials are also of high catalytic efficiency and capable of working at near ambient CO₂ condition owing to their favorable CO₂ selectivity. Given that this organic/inorganic hybrid FLP catalyst features low cost, ease of synthesis, and little requirements on internal structural ordering, it will pave the way for large-scale preparation of amorphous heterogeneous FLP materials toward low-cost, robust, and sustainable C1 conversion.