Superior performance of iron-doped manganese dioxide for low-temperature propane oxidation

Abstract

Iron-doped manganese dioxide has attracted extensive attention in the abatement of propane, but the application potential at low temperatures remains a challenge. Here, a series of low-content Fe-doped manganese dioxides were fabricated via a facile precipitation method with the molecular ratios of Fe : Mn ranging from 1 : 20 to 1 : 100, which were named Fe₁Mn₂₀, Fe₁Mn₂₅, Fe₁Mn₅₀, and Fe₁Mn₁₀₀, respectively. For all the prepared catalysts, propane can achieve 10%, 50%, and 90% conversion at lower temperatures and the Fe₁Mn₅₀ catalyst realizes the most superior catalytic activity with T₉₀ of 230 °C. The Fe₁Mn₅₀ catalyst also exhibits good stability within a continuous experiment of 30 hours at 230 °C. The characterization of the prepared catalysts reveals that iron doping stimulated the formation of oxygen vacancy defects, introduced good oxygen mobility in the catalyst, and hence increased the catalytic performance. The remarkably enhanced catalytic performance of manganese dioxide suggests that trace doping of transition metals is an effective strategy to develop more active metal oxide catalysts.