CO₂ Conversion into Light Olefins Using an InCeZrO_X/H-ZSM-5-Si Bifunctional Catalyst

Carbon dioxide (CO₂) conversion into light olefins (C₂⁼–C₄⁼) using green hydrogen is a desirable strategy to reduce CO₂ emissions and obtain valuable chemicals. Although ZSM-5-based bifunctional catalysts exhibit unique characteristics that render them suitable for various processes, they are rarely used for CO₂ conversion into C₂⁼–C₄⁼. Herein, an In_0.9Ce₁Zr₄O_X/H-ZSM-5-Si bifunctional catalyst composed of In_0.9Ce₁Zr₄O_X and tetraethyl orthosilicate (TEOS)-passivated H-ZSM-5-Si was prepared for CO₂ conversion into light olefins. CO₂ on In_0.9Ce₁Zr₄O_X/H-ZSM-5-Si exhibits a selectivity of 60.3% for C₂⁼–C₄⁼, 5.9% for CH₄, and 17.2% for C₅₊ in hydrocarbons. The CO selectivity in the total products is 63.6%. The doping of In and Ce increases the concentration of surface oxygen vacancies, thereby enhancing the adsorption of CO₂ and H₂. The passivation of H-ZSM-5-Si by TEOS effectively reduces its acidity, promoting the generation of C₂⁼–C₄⁼.