Design catalytic space engineering of Ag-Ag bond-based metal organic framework for carbon dioxide fixation reactions

Chemical fixation of carbon dioxide (CO2) has been regarded as a C1 source into valuable chemical products using cheap industrial chemicals, owing to its abundant supply from the combustion of fossil fuels. The development of efficient and low energy consumption heterogeneous catalysts for cycloaddition with carbon dioxide to produce five-membered cyclic chemical product without any side products under mild reaction conditions is of great importance, yet remains a great challenge. In this work, the coupling reaction of CO2 with propargylamine derivatives by Ag-MOF in the presence of other additives (e.g. reaction time, base, solvent, temperature and pressure) was studied in different conditions. It was discovered that Ag-MOF had excellent synergetic effect in promoting the reaction, and the Ag-MOF/DBU catalytic system was the most efficient among them. The optimal reaction could be completed in 5 h at room temperature under atmospheric CO2 pressure with very high selectivity. A decrease of the yield of the aim product was not noticeable after Ag-MOF catalyst for recycling experiments revealed the stability of the catalysts after five uses. The Ag-MOF catalytic system was also very active and selective for different size and shape reaction substrates.