Catalytic Combustion of Propane over MnNbOx Composite Oxides: The Promotional Role of Niobium

Metal-doping is an efficient strategy to develop high-activity composite metal oxides catalysts for VOCs abatement. Herein, MnNbOx composite oxides were prepared using niobium element as a modification additive, finding that niobium addition presented a promotional effect on boosting the catalytic activity of MnOx for propane combustion. It was demonstrated that niobium insertion into manganese oxides was in favor of the formation of Mn3O4 crystalline phase and concurrently caused higher redox ability, more abundant surface oxygen species, and acid sites. All these properties were considered to be crucial parameters for catalytic activity enhancement. Among all, the catalyst of Mn0.85Nb0.15Ox (simply designated as M0.85N0.15) showed the highest propane conversion efficiency and relatively good catalytic durability under CO2-containing atmospheres. Moreover, the in situ DRIFTs analysis highlighted the important role of surface acidity in the surface catalytic pathways of propane adsorption, activation, and oxidation.

Automated summary

Metal-doping with niobium as a modification additive enhances the catalytic activity of MnOx for propane combustion. Niobium insertion into manganese oxides promotes the formation of Mn3O4 crystalline phase, increases redox ability and surface oxygen species, and provides more acid sites, crucial for catalytic activity enhancement. Mn0.85Nb0.15Ox catalyst shows the highest propane conversion efficiency and good durability under CO2-containing atmospheres, with surface acidity playing an important role in propane adsorption, activation, and oxidation pathways.