Photoinduced Reaction Pathway Change for Boosting CO2 Hydrogenation over a MnO-Co Catalyst

Developing low-cost catalytic materials to utilize both solar and thermal energy and unveiling the photoinduced reaction pathway change mechanism are highly desirable for photothermo catalytic CO2 hydrogenation. Here, a low-cost Co-supported MnO catalyst is predesigned and synthesized as a model PTC catalyst. Under PTC conditions (1.0 W cm(-2)), the activity and C2+ selectivity are 3- and 2-times higher than those of the traditional thermal catalytic conditions (150 degrees C). The wavelength-dependent performance enhancement, in situ diffuse reflectance infrared Fourier transform spectroscopy, and in situ ambient pressure X-ray photoelectron spectroscopy reveal that the photoenhanced strong metal-oxide interaction between Co and MnO can enrich electrons of Co to induce the different initial hydrogenation reaction pathways. The distinct reaction pathway changes from the formate mechanism under TC conditions to the reverse water-gas shift followed by subsequently *CO hydrogenation (RWGS-CO hydro) under PTC conditions. Furthermore, such a photoinduced pathway change leads to a lower activation energy barrier, thus promoting CO2 hydrogenation under PTC conditions.

Automated summary

The study introduces a low-cost Co-supported MnO catalyst for photothermo catalytic CO2 hydrogenation, exhibiting higher activity and selectivity compared to traditional thermal conditions. By enhancing the metal-oxide interaction, the reaction pathway is altered, leading to improved catalytic performance for CO2 hydrogenation.