Highly efficient solar-driven CO2-to-fuel conversion assisted by CH4 over NiCo-ZIF derived catalysts

Abstract Solar-driven CO2 reduction by CH4 is promising to simultaneously tackle energy shortage and global warming problems by converting two greenhouse gases into fuels. However, serious challenges remain, such as limited light-to-fuel efficiency, high operating temperature, and severe catalyst deactivation. Here, high-performance direct solar-driven CO2 reduction is demonstrated at relatively low operation temperature (594 °C) based on NiCo-ZIF derived nanostructures. An ultrahigh light-to-fuel efficiency of 32.4% and production rates of H2 (105.83 min−1g−1) and CO (128.17 mmol min−1g−1) are achieved via photothermocatalysis on Ni1Co2@CZIF-Al2O3 catalysts. Excellent light-to-fuel conversion performance can be attributed to the highly dispersed metal particles, decreased apparent activation energy under direct light illumination, increased CO2 absorption, and promoted dissociation of CH4 to CH3* of NiCo alloy. The carbon deposition rate of NiCo bimetallic catalysts is prominently inhibited compared with pure Ni or Co catalysts due to the change of the reaction path, as confirmed by DFT calculations. This work opens new routes to achieve highly efficient solar-driven CO2 reduction by CH4 based on NiCo-ZIF derived alloy nanostructures at relatively low-temperature conditions.