Photocatalytic CO2 reduction to C1-C5 hydrocarbons using K2Fe2O4/g- C3N4 as coupling photocatalyst

A particularly interesting and difficult research topic is converting inexpensive and abundant single -carbon (C1) molecules to high-value multicarbon (C2+) molecules, especially to improve selectivity and conversion efficiency. Photocatalytic reduction offers a green technique for activating C1 molecules and controllable C-C coupling under mild and environmentally friendly conditions. This study synthe-sizes K2Fe2O4/g-C3N4 as a magnetic ferrite-containing photocatalyst for the C-C coupling of CO2 in the absence of a sacrificial agent. The findings significantly advance the photocatalytic conversion of CO2 into C2+ compounds, particularly CnH2n+2, CnH2n, and CnH2n_2 (n = 1-5), which are crucial in the chemical and energy industries. The photocatalyst, which has a remarkable selectivity to hydrocarbons (52% CH4, 48% C2+), was optimized to achieve the optimum progressive selective conversion from CO2 to CH4 and finally to C2+ hydrocarbons. The optimized K2Fe2O4/g-C3N4 shows an optimal CO2 to CH4 conversion rate of 130.96 mmol/g/h, which is 6.27 and 8.60 times the reaction rate constant of K2Fe2O4 and g-C3N4 as catalysts, respectively. It is speculated that this study will help understand the activation of CO2 in photocatalytic reduction and the highly selective production of hydrocarbons via the C-C coupling reaction.& COPY; 2023 Elsevier Ltd. All rights reserved.