Dendritic mesoporous silica nanosphere supported highly dispersed Pd-CoOx catalysts for catalytic oxidation of toluene

Catalytic oxidation is an effective way for toluene-bearing VOCs removal. A series of Co-grafted dendritic mesoporous silica nanospheres (Co-DMSNs-f) were synthesized by the controlled grafting method. The catalysts show superior micro-structure, high dispersion of CoOx species and proper metal-support interaction. For comparison, corresponding DMSNs-supported CoOx samples were prepared by impregnation method. Co-grafted DMSNs samples yield better structure stability. For the Co-grafted DMSNs, moisture is involved in the activation of O-2 and exhibits a short and reversible negative effect on catalytic activity. The influence of Pd-modification on the Co-containing catalysts was also investigated and the introduction of Pd can markedly enhance the catalytic performance. The supported catalysts generate proper CoOx-SiO2 and Pd-CoOx interactions. The Pd-CoOx interface can further influence the synergistic effect in oxygen activation and toluene adsorption. The tunable CoOx-support and Pd-CoOx interactions play an important role in the toluene oxidation.

Automated summary

Catalytic oxidation of toluene-bearing VOCs can be effectively achieved using Co-grafted dendritic mesoporous silica nanospheres. The catalysts exhibit superior micro-structure, high dispersion of CoOx species, and proper metal-support interaction. The presence of moisture negatively affects the catalytic activity but this effect is reversible. Introducing Pd into the catalysts significantly enhances the catalytic performance by influencing the oxygen activation and toluene adsorption synergistic effect.