Efficient reduction of CO2 and inhibition of hydrogen precipitation by polyoxometalate photocatalyst modified with the metal Mn

Abstract

Photocatalytic reduction of CO₂ to chemical fuels is attractive for solving both the greenhouse effect and the energy crisis, but the key challenge is to design and synthesize photocatalysts with remarkable performance under visible light irradiation. Efficient catalytic carbon dioxide reduction (CO₂RR) with light is considered a promising sustainable and clean approach to solve environmental problems. Herein, we found a new photocatalyst ([Mn(en)₂]₆[V₁₂B₁₈O₅₄(OH)₆]) (abbreviated as Mn₆V₁₂) based on the modifiability of polyoxometalates, in which Mn acts as a modifying unit to efficiently reduce CO₂ to CO and effectively inhibit the hydrogen precipitation reaction. This Mn modified polyoxometalate catalyst has a maximum CO generation rate of 4625.0 μmol g⁻¹ h⁻¹ and a maximum H₂ generation rate of 499.6 μmol g⁻¹ h⁻¹, with a selectivity of 90.3% for CO generation and 9.7% for H₂ generation. This polyoxometalate photocatalyst can effectively reduce CO and inhibit the hydrogen precipitation reaction. It provides a new idea for the efficient photocatalytic carbon dioxide reduction (CO₂RR) with polyoxometalate catalysts.