Eco‐Friendly Coordination Polymers with Incorporated Nitrogen‐Rich Heterocyclic Ligand and Their Hybrids with Gold Nanostructures for the Sustainable Conversion of Carbon Dioxide

This paper demonstrates the successful synthesis of novel hybrid heterogeneous catalysts for the sustainable conversion of CO2 into cyclic organic carbonates (COCs). The nanocat-alysts have been fabricated by encapsulating pre-formed ultra-small gold nanostructures into a nascent zinc-coordination polymer (ZnCP) framework formed from two organic building blocks: 2,4-naphthalenedicarboxylic acid (1,4-NDC) and 5-amino-1H-tetrazole (5-Atz), which serves as a nitrogen-rich ligand. Applying the fabri-cated catalysts in the synthesis of COCs yields high yields (up to 97%) and high selectivity (up to 100%), with exceptionally high turnover frequencies (TOFs) (up to 408 h-1). The cat-alytic process can be carried out under mild conditions (80°C, 1.5 MPa CO2) and without the use of solvents. Nitrogen-rich ligand molecules in the structure of ZnCPs enhance catalytic performance thanks to additional nucleophilic centres, which are effective in the epoxides' ring-opening process. The hybrid catalysts with encapsulated gold nanostructures, which modify the liquid-gas interface between epoxide and CO2, give significantly higher yields and TOFs for less active epoxides. The designed hybrid nanocatalysts exhib-it superior stability under the studied reaction conditions and can be reused without loss of activity. The developed coordination polymers are built of green components, and green chemistry principles are employed to prepare these catalytic materials.