Continuous photothermal gas-phase CO2 hydrogenation over highly dispersed Ru-Ni on TiO2

Abstract

Photocatalytic and photothermal carbon dioxide (CO₂) hydrogenation are investigated as key strategies for CO₂ depletion by transformation into valuable products. Ni and Ru are well known Sabatier's reaction catalysts. In the present work we study their activity as Ni, Ru and bimetallic nanoparticles over the surface of titanium dioxide (TiO₂) in the photocatalytic reduction of CO₂, following a process of photo-assisted deposition that yield highly dispersed nanoparticles with sizes under 2 nm. Outstanding production of solar fuels was observed from Ni and Ru 2-nm nanoparticles deposited onto P25 TiO₂. The photocatalytic activity tests under light irradiation from low-energy LEDs at different wavelengths, from UV-A at 365 nm to infrared at 940 nm at 523 K, rendered up to 6 % CO₂ conversion under continuous feed, with CO and CH₄ productivities above 5 mmol/g_cat·h.