Cobalt-porphyrin modified graphene oxide as a heterogeneous catalyst for solvent-free CO2 fixation to cyclic carbonates

Chemical fixation of carbon dioxide into commodity chemicals is an appealing approach for CO2 transformations and utilizations. The challenge is to develop highly efficient and reusable heterogeneous catalysts. Herein, a cobalt-porphyrin modified graphene oxide (GOPCoCl) has been prepared with chemical functionalization by the acylation and amidation process on the graphene oxide support, and applied as a heterogeneous catalyst for the solvent-free cycloaddition of carbon dioxide and epoxides. The as-received GOPCoCl has been characterized by different methods, demonstrating that the metalloporphyrin is covalently linked to the graphene oxide (GO) surface. Owing to the uniform active sites and support effects, the catalyst behaved efficient catalytic performance, excellent recyclability, and good substrate expansibility for this solvent-free cycloaddition. Moreover, a synergetic catalytic mechanism has been prudently proposed based on the catalytic system and experimental results.