Catalytic Properties of ZnZrOx Obtained via Metal–Organic Framework Precursors for CO2 Hydrogenation to Prepare Light Olefins

The conversion of CO2 into light olefins over bifunctional catalysts is a promising route for producing high-value-added products. This approach not only mitigates excessive CO2 emissions but also reduces the chemical industry’s reliance on fossil fuels. Among bifunctional catalysts, ZnZrOx is widely used due to its favorable oxide composition. In this work, ZnZrOx solid solution was synthesized by calcining an MOF precursor, resulting in a large specific surface area and a small particle size. Characterization studies revealed that ZnZrOx prepared via MOF calcination exhibited an enhanced CO2 activation and H2 dissociation capacity compared to that synthesized using the co-precipitation method. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) showed that CO2 adsorption on ZnZrOx led to the formation of carbonate species, while HCOO* and CH3O* intermediates were generated upon exposure to the reaction gas. When ZnZrOx was combined with SAPO-34 molecular sieves under reaction conditions of 380 °C, 3 MPa, and 6000 mL·g_cat−1·h−1, the CO2 conversion reached 34.37%, with a light olefin yield of 15.13%, demonstrating a superior catalytic performance compared to that of the co-precipitation method.