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The preparation circumstances and effects of the kaolin-modified SAPO-34 molecular sieves were studied in order to support the industrial application of the cutting-edge technology for producing light olefins from syngas catalyzed by bifunctional catalyst. Additionally, their apparent morphology, crystal structure, structural features, and acid strength were tested. The results demonstrated that kaolin-based molecular sieves are thinly layered and have an acid strength and pore structure that are more conducive to reactions. The effect of the mass ratio of the oxide to the molecular sieve, the hydrogen to carbon ratio of the feed gas, and other reaction conditions on the catalytic activity of the bifunctional catalyst was investigated using modified molecular sieves. Under the reaction conditions of the oxide to molecular sieve mass ratio of 2:1, feed gas composition of n(H2)/n(CO) = 2, 400 °C, and 3 MPa, a CO conversion of 50.11% with a low CO2 selectivity of 17.01% and a light olefins yield of 24.18% could be achieved. [ABSTRACT FROM AUTHOR]

A key primary method for creating a carbon cycle and carbon neutrality is the catalytic hydrogenation of CO2 into high value‐added chemicals or fuels. In this work, ZnGaOx oxides were prepared by parallel co‐precipitation and physically mixed with SAPO‐34 molecular sieves prepared by hydrothermal synthesis to produce ZnGaOx/SAPO‐34 bifunctional catalysts, which were evaluated for the catalytic synthesis of lower olefins (C2=−C4=) from carbon dioxide hydrogenation. It was demonstrated that the reaction process requires oxygen defect activation, synergistic hydrogenation, and CO2 alkaline adsorption of ZnGaOx. The spinel structure of ZnGaOx has more abundant oxygen defects and alkaline adsorption sites than the ZnGaOx solid solution, which effectively enhances the catalytic performance. The CO2 conversion was 28.52%, the selectivity of C2=−C4= in hydrocarbons reached 70.01%, and the single‐pass yield of C2=−C4= was 10.95% at 370 °C, 3.0 MPa, and 4800 mL/gcat/h. [ABSTRACT FROM AUTHOR]