Oxidative Dehydrogenation of Propane with Carbon Dioxide Catalyzed by ZnxZr1–xO2–x Solid Solutions

Although the oxidative dehydrogenation of propane with CO2 (CO2-ODP) is a sustainable route for producing propylene with the tandem conversion of CO2 to the value-added CO, its industrialization is still challenged by the lack of an efficient catalyst, which originates from the insufficient understanding of the catalytic nature and reaction mechanism. In this work, ZnO-ZrO2 composites were probed as catalysts for CO2-ODP. A pure ZnxZr1–xO2–x solid solution was formed over ZnO-ZrO2 composites with 5–20 mol % ZnO, and the content of oxygen defects was almost directly proportional to the fraction of the solid solution. The amount and the mobility of lattice oxygen over ZnxZr1–xO2–x solid solutions were revealed as key factors in determining the catalytic performance. The CO2-ODP reaction over the best 20 mol %ZnO-ZrO2 catalyst occurred almost stoichiometrically via the redox mechanism, which can be an important guideline for further developing a high-performance catalyst for CO2-ODP.