Dual-Function Precious-Metal-Free Metal–Organic Framework for Photocatalytic Conversion and Chemical Fixation of Carbon Dioxide

Abstract

Highly efficient transformation of carbon dioxide (CO₂) into value-added chemicals is considered a promising route for clean production and future energy sustainability, which is crucial for realizing a carbon-neutral economy. It remains a great challenge to develop highly stable and active catalysts with low-cost, environmentally friendly, and nontoxic materials for catalytic conversion of CO₂. Herein, a precious-metal-free and heterogeneous MOF (<b>LTG</b>-<b>FeZr</b>) catalyst, composed of bis(terpyridine)iron(II) complexes and zirconium(IV) ions, was designed and prepared via a metalloligand approach. <b>LTG</b>-<b>FeZr</b>, with a robust framework and regular 1D channels not only can achieve the photocatalytic reduction of CO₂ to HCOOH with a high conversion rate (up to 265 μmol·g^-1·h^-1) under visible-light irradiation but also exhibits exceptional catalytic activities toward the synthesis of cyclic carbonates via cycloaddition reactions of various epoxides and CO₂ in the absence of light. Possible mechanisms for two different conversion processes of CO₂ catalyzed by <b>LTG</b>-<b>FeZr</b> have been proposed. <b>LTG-FeZr</b> represents an ideal dual-function MOF platform for the catalytic conversion and utilization of CO₂ in all weather conditions.