CO2 oxidative dehydrogenation of n-butane to butadiene over CrOx supported on CeZr solid solution

1,3-Butadiene (BD) is a key raw material for the synthesis of rubber, but its efficient synthesis is a challenge. Direct dehydrogenation of n-butane in CO2 (CO2ODHB) represents an ideal way to produce BD and use the waste CO2 source. In the present work, several catalysts of CrOx supported on CeZr solid solutions were developed and applied in catalyzing the CO2ODHB to BD. Among these, a 10%CrOx/Ce0.5Zr0.5O2 could achieve the reaction with 25% of n-butane conversion and 70% of BD selectivity at 823 K. The prepared catalysts were characterized using the techniques of XRD, UV–vis-DR, XPS, Raman, N2 adsorption/desorption, FT-IR, TEM, H2-TPR, NH3-TPD, and CO2-TPD, etc. The results indicated that compared with other catalysts, the 10% CrOx/Ce0.5Zr0.5O2 catalyst possessed the highest Cr6+ species concentration and balanced acidic-basic sites, contributing to the outstanding performance in the reaction. These findings provide a strategy to build a catalyst with the stable valence of Cr6+ species, and hopefully, offer an important reference to establish other CeZr solid solution catalysts with regulable acidic-basic and textural properties.