Rebuilding supramolecular aggregates to porous hollow N-doped carbon tube inlaid with ultrasmall Ag nanoparticles: A highly efficient catalyst for CO2 conversion

Fabrication of novel heterogeneous catalysts with well-designed structures is unusually intriguing for CO2 conversion. In this study, we have prepared a porous hollow N-doped carbon tube through the pyrolysis of self-assembled melamine cyanurate aggregate supramolecular precursor. Ultrasmall Ag nanoparticles were tightly anchored in the hollow N-doped carbon tube via an in-situ fabrication. The average size of Ag nanoparticles was confined in only 2.19 nm with the assistance of abundant surface functional groups and porous structures. Additionally, inherent hollow N-doped carbon tube structure could prevent nanoparticles aggregating and leaching; also, they facilitated gas adsorption and mass transfer in CO2 catalysis. Due to their remarkable properties, the novel material was utilized as heterogeneous catalyst for the carboxylation of alkynes with CO2, and exhibited outstanding catalytic activity and stability at ambient pressure and low temperature.