Defect structure and species allocation of Mn-Ce/NbOPO4 surface by pH regulation

The support plays significant role in oxide-supported noble metal catalysts, which could provide the stability and dispersion of active species. NbOPO4 with strong surface acidity is a potential replacement for traditional supports, which could enhance the water and sulfur resistance obviously. In this study, the surface defects and species assignment of the support was altered by adjusting pH value. It was found that neutrality contributes the formation of porous structure. The surface defects of the support could assist the active components to trap oxygen and are beneficial for catalytic reactions. The abundant [NbO6] groups on the surface can improve the water and sulfur resistance of the catalyst. The electron transfer reaction between Nb5+ and Mn3+ on the support surface produces a large number of oxygen defects, which helps to improve the oxidation-reduction capacity of the catalyst.