Catalytic Combustion of Propane over MnNbO<sub><i>x</i></sub> Composite Oxides: The Promotional Role of Niobium
Kai Zeng, Yating Wang, Changfei Huang, Hanchen Liu, Xuehua Liu, Zhong Wang, Jun Yu, Chuanhui Zhang
Abstract
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.