Cu‐based mixed metal oxide catalysts for WGSR: Reduction kinetics and catalytic activity

Abstract

AbstractThis communication reports the effects of Mn/Cr on the reducibility and catalytic activity of Cu–Fe–Mn and Cu–Fe–Cr mixed oxide catalysts for the water gas shift reaction (WGSR). The reduction kinetics of the mixed oxide catalysts is investigated using TPR data, nucleation/nuclei growth models, and a power law model. Based on the statistical indicators, it is concluded that a second‐order power law model describes the reduction of all catalysts adequately. The estimated activation energy for the reduction of the Cu–Fe–Mn catalyst is low compared to the Cu–Fe–Cr catalyst. The TPR analysis of the catalysts reveals that the addition of Mn significantly improved the reducibility of Cu‐oxide species, which is consistent with the low activation energy for reduction of the Cu–Fe–Mn catalyst. In a flow type reactor, the Cu–Fe–Mn catalyst showed highest CO conversion at around 220°C, achieving a high specific reaction rate compared to the Cu–Fe–Cr catalyst. The enhanced reducibility of Cu–Fe–Mn catalyst played the key role in the high conversion of CO. These results are comparable with the results obtained for a commercial Cu–ZnO/Al2O3 catalyst, which was evaluated under the same reaction conditions.