Abstract
Development of non-platinum cathode catalysts for polymer electrolyte fuel cell (PEFC) is one of the indispensable subject for broad commercialization of PEFC. The requirements of cathode catalysts for PEFC are stability in strong acidic conditions, appropriate electroconductivity, and high surface area as well as activity of reaction sites. Oxide and nitride catalysts of group 4 and 5 element, such as Ti, Nb, Ta, and Zr, has obvious resistivity for strong acidic conditions as same as the precious metals, so that they are expected to be applied to cathode catalysts. With nano-sizing of catalyst particles, these materials show obvious activity. This article stands on the recent achievement of developments of non-platinum cathode catalysts of oxide and nitride catalysts of group 4 and 5 elements, such as Ti, Nb, Ta, and Zr reported by our group.
