Metal and Co-Catalyst Free CO2Conversion with a Bifunctional Covalent Organic Framework (COF)

The excessive growth of CO(2)brings about the global warming and subsequent climate change, which is an increased public concern issue. Currently, the chemical fixation of CO(2)is identified as one of the most effective approaches to reduce and utilize CO2. Thus, it is a great challenge to rationally design and construct high-efficient catalysts for CO(2)conversion and utilization. Here, a unique metal-free bifunctional COF heterogeneous catalyst was successfully achieved via the post-modified strategy, which simultaneously bears -COOH as Bronsted acidic center and Br(-)ion as nucleophilic active site. By virtue of abundant porosity, excellent stability, favorable CO(2)adsorption, and dual catalytic sites, this material can efficiently facilitate the coupling reaction of CO(2)with epoxide to form cyclic carbonate without co-catalyst under mild conditions. Moreover, it has excellent reusability, without significant reduction of the catalytic activity after at least five cycles.