Synergistic performance of novel Cu-MOF-74@SBA-15 material in enhanced CO2 adsorption and transformation

Abstract

Eight cost-effective MOF@OMM (Ordered Mesoporous Material) novel hybrid materials composed of SBA-15 and Cu-MOF-74 have been developed for CO₂ capture and conversion. Using a systematic synthesis approach, variables such as impregnation solvent, the copper molar concentration in the impregnation solution, and the MOF crystallization time were varied to find the material with the optimum features for CO₂ adsorption and transformation via cycloaddition reaction using epoxides. All synthesized materials were tested in CO₂ adsorption at 0 and 45°C to assess their CO₂ adsorption capacity at up to 8 bar. Remarkably, CO₂ adsorption per mmol of copper is higher for the hybrid Cu-MOF-74@SBA-15 materials than for the sole Cu-MOF-74 and SBA-15, revealing a cooperation effect between both structures. Additionally, as heterogeneous catalysts in CO₂ cycloaddition, the hybrids achieved higher epoxide conversion and turnover numbers than Cu-MOF-74 alone when the same catalyst mass was used. This improved performance comparable to pure MOF with less copper content is attributed to the enhanced dispersion and reduced crystal size of the MOF within the SBA-15 support, increasing accessibility to active sites and resulting in superior catalytic activity and CO₂ adsorption efficiency. This study highlights the potential of these hybrids as cost-effective, sustainable candidates for carbon mitigation solutions.