Influence of hierarchically porous niobium doped TiO₂ supports in the total catalytic oxidation of model VOCs over noble metal nanoparticles

An Nb doped, hierarchically micro(meso)macroporous TiO₂ (anatase phase) was synthesised via a facile self-formation procedure and employed as a catalytic support, combining the advantages of a promoter with improved diffusion through the intrinsic macroporous network. The efficiency of the catalytic systems in the total oxidation of butan-1-ol and toluene was determined. Niobium was found to promote catalytic activity, with minimal secondary products. Indications suggest that reduction of the catalyst occurs at lower temperatures with an Nb dopant owing to stronger support-metal interactions, which boosts efficiency. This study found that noble metals, Pd and Pt, behave differently when deposited on Nb-TiO₂ with Pt benefiting most from Nb doping, with a marked increase in activity and CO₂ selectivity whereas Pd catalysts have improved low temperature activities. This work highlights the feasibility of economic and energetic reductions by minimising catalyst loading in favour of cheaper catalytic promoters and a reduction in operational temperature during VOC remediation.