Coordination of few-atomic Pt clusters with Mo to boost the hydrogenation reduction of bromate

Abstract

Here, we prepared microporous carbon (PC) supported Pt catalysts with different isolated Pt atoms and designed pathways to introduce Mo into the catalysts. Bromate (BrO3−) was applied as the model oxyanion to evaluate the hydrogenation decontamination efficiency and catalyst activity. At a catalyst dosage of 0.05 g l−1, BrO3− was reduced by 98.3 % after reaction for 30 min over Pt2-PC with Pt atomic clusters, much higher than that of single atom (Pt0.5-PC, 5.1 %) and nanoparticle (Ptn-PC, 43.2 %) counterparts. H2 was dissociated in a heterolytical manner on the highly isolated Pt active sites and the formed active H+/H− pairs dominated the removal of BrO3− supported by the experimental data and density functional theory (DFT) calculation. High-valent Mo in the solution could be reduced to lower valent by consecutive active H, which further joined BrO3− reduction directly. In comparison, Mo atoms anchored on PC substrate scrambled N ligands with Pt, favoring the enrichment of BrO3− anions on the catalyst surface, thus the generated active H could react with the nearby BrO3− instantly. This study highlights the role of few-atomic Pt clusters for H2 activation and provides a strategy to boost the liquid phase catalytic hydrogenation reaction.