NAP-XPS study of Eu3+ → Eu2+ and Ce4+ → Ce3+ reduction in Au/Ce0.80Eu0.20O2 catalyst

Eu3+ → Eu2+ and Ce4+ → Ce3+ reduction in Au/Ce0.80Eu0.20O2 catalyst were systematically studied using in-situ NAP-XPS technique. The reduction of Eu3+ → Eu2+ in the ceria, in a hydrogen atmosphere at temperature ≥ 400 °C, has been demonstrated for the first time. The effect of the reduction of Ce0.80Eu0.20O2 support on the catalytic activity of Au nanoparticles in CO oxidation has been investigated.