Bifunctional catalyst Ga2O3-mZrO2/SAPO-34 for CO2 hydrogenation: Ga2O3-mZrO2 improving light olefins

Abstract

CO₂ hydrogenation to light olefins is key for reducing environmental emissions and creating sustainable energy. Bifunctional oxide–zeolite (OX–ZEO) catalysts are widely used in this area. Metal oxides, crucial for CO₂ adsorption and H₂ dissociation, need careful selection and optimization. This paper presents a bifunctional catalyst where Ga₂O₃ is loaded onto mZrO₂ (monoclinic zirconia) (Ga₂O₃-mZrO₂) using citric acid complex method and combined with SAPO-34. Our study demonstrates that the loading method can significantly improve the adsorption capacity of the catalyst for CO₂ and had demonstrated impressive catalytic performance compared to common preparation methods. Further, Ga₂O₃-mZrO₂, in comparison to Ga₂O₃ loaded onto tZrO₂ (tetragonal zirconia) (Ga₂O₃-tZrO₂), has a stronger ability to produce light olefins. The catalyst achieves 84.1% selectivity for C₂⁼–C₄⁼, 20.2% CO₂ conversion, and 45.3% CO selectivity, remaining stable over 100 hours. This offers a novel method for designing highly active Zr-based oxides for effective CO₂ conversion.