Engineering multi-component 3DOM FeVCrOx catalysts with high oxygen mobility for the oxidative dehydrogenation of 1-butene with CO2

Abstract

Oxidative dehydrogenation (ODH) of 1-butene with CO2 to 1,3-butadiene (BD) via Fe-based catalysts is a promising strategy, and the mobility of lattice oxygen plays a key role in the catalytic reaction. However, the catalytic activity of Fe-based catalysts is limited by the poor lattice oxygen mobility. To improve the mobility of lattice oxygen and optimize the ODH reaction, a series of 3DOM Fe-based catalysts (FeVAlOx, FeCrAlOx, and FeVCrAlOx) were prepared by PMMA template method. Among these samples, the multi-component FeVCrAlOx samples showed the best catalytic activity, and the 1-butene conversion of the multi-component catalyst could reach 88.3 %, the BD yield could reach 27.5 %. Further study found that the introduction of multi-component elements (V and Cr) not only promoted the formation of the γ-Fe2O3 phase but also formed more active components (V5+ and Cr6+). More importantly, the lattice oxygen mobility was also significantly improved. In addition, the reaction in the presence of water conditions was studied by activity tests and in-situ DRIFTS tests. The results show that CO2 was present in the form of HCO3-. The utilization of CO2 was improved and the reaction path was changed.