Gold–indium modified TiO2 nanocatalysts for photocatalytic CO2 reduction with H2 as reductant in a monolith photoreactor.

Abstract:

In this study, CO₂ photoreduction via reverse water gas shift (RWGS) reaction over gold (Au) and indium (In) modified TiO₂ nanocatalysts in a monolith photoreactor has been investigated. Crystalline nanoparticles of anatase TiO₂ were obtained in doped TiO₂ samples with metals deposited over TiO₂ as Au and In³⁺ ions. The catalytic performance of metal-doped/TiO₂ catalysts was found to be considerably higher when compared to pure TiO₂. The maximum production of CO as the main product was 8982 μmol g-catal⁻¹ h⁻¹ at selectivity 99% and CO₂ conversion of 9.5% over 0.2 wt.% Au–3.5 wt.% In/TiO₂, and CO₂/H₂ feed ratio 1.5. The CO production over co-metals (Au–In) doped TiO₂ monolithic catalyst was 1.3 times higher than Au/TiO₂, 4.39 times higher than In/TiO₂ and 76 times higher than un-doped TiO₂ catalysts. Significantly higher photoactivity of metal-doped TiO₂ was obviously due to fast electron transfer with hindered recombination rates and larger illuminated surface area in monolith channels. The quantum efficiency of CO production through RWGS reaction using Au–In/TiO₂ catalyst was considerably improved (0.79%) than Au/TiO₂ (0.53%) and In/TiO₂ (0.14%) monolithic catalysts. The stability of the reused catalysts for CO production sustained at cyclic runs. This development confirmed higher performance of metals-doped TiO₂ nanocatalysts supported over monolith channels for CO₂photoreduction via RWGS reaction

1. Beenish Tahir, Muhammad Tahir and Nor Aishah Saidina Amin (2015). Gold–indium modified TiO2 nanocatalysts for photocatalytic CO2 reduction with H2 as reductant in a monolith photoreactor. Applied Surface Science, 338, 1-14. DOI: https://doi.org/10.1016/j.apsusc.2015.02.126