Activity-enhanced Cu@ZIF-8/Ag carbonic anhydrase mimic for CO2 hydration and conversion

Abstract

Carbonic anhydrase (CA) is an enzyme with unrivaled catalytic activity for CO2 hydration reactions. However, its high cost and poor stability have severely limited its industrial application in CO2 uptake. Constructing CA mimics is a promising strategy to overcome these limitations. In this work, a novel ZIF-8-based CA mimic, Cu@ZIF-8/Ag, was fabricated for CO2 capture and storage. Esterase experiments confirmed that Cu@ZIF-8/Ag had higher CA-mimicking activity than ZIF-8 and Cu@ZIF-8, indicating that Cu-doping and in-situ growth of Ag nanoparticles significantly increased CA-like activity. Simulating the mineralization process in industrial applications, Cu@ZIF-8/Ag yielded the highest CaCO3 yields. Additionally, Cu@ZIF-8/Ag has good reusability, with catalytic activity over 10 % higher than ZIF-8 even after seven adsorption and regeneration cycles. This activity-enhanced Cu@ZIF-8/Ag carbonic anhydrase mimic shows great potential for future CO2 capture.