EFFECT OF NIOBIUM DOPING FOR ENHANCING ORR ACTIVITY OF NIOBIUM DOPED TITANIUM OXIDE ELECTRO-CATALYST

Abstract

We performed the structure analysis of Nb doped titanium oxides oxygen reduction electro-catalysts in order to understand the effect of Nb doping on enhancing oxygen reduction reaction activity. Nb doping makes effects on stabilization of anatase phase of TiO2 with high ORR activity, lowering of particle size, and introduction and increment of Ti3+related to the ORR active sites. Large amount of Nb doping causes the suppression of ORR activity due to the covering of ORR active sites by non-active outer layers contain rutile, Ti4O7, and TiNb2O7 phases.