A Highly Stable Triazole-Functionalized Metal-Organic Framework Integrated with Exposed Metal Sites for Selective CO2 Capture and Conversion

Abstract

A new triazole-functionalized tetracarboxylic acid ligand (H₄ L) has been synthesized and utilized for the fabrication of a 3D Zn^II organic framework with a Zn₄ (-COO)₆ cluster as the secondary building unit. The framework exhibits very good thermal stability and consists of dual functionalities of exposed Lewis acidic metal sites and accessible nitrogen-donor Lewis basic sites. The Lewis basic nitrogen sites in the framework serve as CO₂ binding sites for highly selective CO₂ capture and the presence of exposed Lewis acidic metal sites in the framework make it an efficient heterogeneous catalyst for the chemical fixation of CO₂ into value-added cyclic carbonates under ambient conditions.

Keywords: Lewis acids; Lewis bases; carbon dioxide capture; heterogeneous catalysis; metal-organic frameworks.