Catalyst, production process therefor and use thereof

摘要

The invention provides catalysts which are not corroded in acidic electrolytes or at high potential and have excellent durability and high oxygen reducing ability. The catalysts include a niobium-containing oxycarbonitride having I2/(I1+I2) of not less than 0.25 wherein I1 is the maximum X-ray diffraction intensity at diffraction angles 2theta of 25.45 to 25.65 degrees and I2 is the maximum X-ray diffraction intensity at diffraction angles 2theta=2theta of 25.65 to 26.0 degrees according to X-ray powder diffractometry (Cu-Kalpha radiation).