Effect of Oxygen Spillover on Stable Ni3Fe1 Alloy for High-Performance Dry Reforming of Methane

Abstract

Ni–Fe alloy catalysts represent promising alternatives for dry reforming of methane (DRM). However, the strong affinity of Fe for oxygen caused progressive Fe segregation on the alloy, leading to a decline in catalytic properties. Herein, we explored an efficient approach to create highly dispersed CeO₂ clusters on an Al₂O₃ support for anchoring the stable Ni₃Fe₁ alloy using the oxygen spillover effect. CH₄ and CO₂ conversions as well as the H₂/CO ratio were maintained at 73.7%, 81.6%, and 0.87 at 700 °C, respectively, on the optimal Ni₃Fe₁/1CeO₂–16Al₂O₃. This catalyst featured plentiful oxygen vacancies, strong interactions between the metal and support, and moderate CO₂ activation centers. These collective effects enable the oxygen spillover from FeO_x toward the proximate vacancies on CeO₂. These oxygen species were consumed along with the generation of vacancies by carbon species. The oxygen spillover effect could not only stabilize the alloy structures but alleviate carbon deposition in DRM.