Bio-Inspired Iron-Based Carbonic Anhydrase Mimic for CO₂ Hydration and Conversion

Abstract

CO 2 conversion by stable, cost-effective carbonic anhydrase (CA)-like nanozymes emerges as an efficient and sustainable approach for CO 2 fixation. In this work, a novel iron-based nanomaterial (Fe10@CN-Mg) was first reported to be a CA mimic, in which FeN x sites and Mg(OH) 2 play a synergistically catalytic effect for CO 2 conversion. Although this material has much lower metal content and cost, it has comparable kinetic constants (K m 6.37 mM and V max 30.74 mM/min) and a significantly higher CaCO 3 formation rate (20.60 g•g −1 •h −1 , the quality of CaCO 3 produced per hour per gram of the catalyst) than that of reported CA mimics. Fe10@CN-Mg is stable when processed at extreme pH, high temperature, organic solvents, and high ionic strength and also retains high activity after long storage times (two months) and seven cycles. In addition, Fe10@CN-Mg was successfully applied to convert CO 2 into cyclic carbonates with high economic efficiency.