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

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 gamma-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.