Photocatalytic CO2 reduction to CO over Fe-loaded TiO2/Nanoclay photocatalyst

Abstract

Fe-promoted titanium dioxide (TiO2) nanoparticles dispersed in Montmorillonite (MMT) clay for dynamic photocatalytic carbon dioxide (CO2) reduction to carbon monoxide (CO) and hydrocarbons in a monolith photo-reactor has been investigated. MMT-clay supported Fe/TiO2 nanocomposites were prepared by a controlled and direct sol-gel method and were dip-coated over the monolith micro-channels. The performance of Fe-loaded MMT/TiO2 nano-catalyst for CO2 reduction by H2 toward CO evolution was evaluated in a continuous operation of photo-reactor under UV-light irradiation. The photo-Activity of TiO2 catalyst dispersed in MMT and loaded with Fe was significantly enhanced. The maximum yield of CO over 3 wt% Fe - 10 wt% MMT-loaded TiO2 catalyst reached to 289.30 μmole g-cat-1 h-1 at selectivity 99.61 %, is considerably higher than the amount produced over the MMT/TiO2 (25.95 μmole g-cat-1 h-1) and the pure TiO2 (8.52 μmole g-cat-1 h-1) catalyst. The other products observed with adequate amounts were CH4 and C2H6. These results revealed significantly enhanced photo-Activity of TiO2 loaded with Fe and dispersed over MMT. The enhanced CO evolution was evidently due to larger illuminated active surface area, higher adsorption process inside the monolith micro-channels and hindered charges recombination rate by Fe. This development has confirmed higher photoactivity of Fe-MMT/TiO2 photo-catalyst for continuous CO2 photo-reduction to cleaner fuels.