Catalytic strategies for CO2 hydrogenation to BTX and p-xylene: A sustainable approach towards carbon neutrality

Abstract

In recent decades, the substantial rise in atmospheric carbon dioxide (CO₂) levels has raised significant environmental concerns, such as global warming and ocean acidification. As a result, reducing carbon emissions and the interest in carbon neutrality have emerged as vital global goals to protect the environment and society. The hydrogenation of CO₂ to produce BTX (benzene, toluene, xylene), particularly p-xylene (PX), provides a sustainable pathway for CO₂ transformation toward valuable chemical feedstocks. This review presents an overview of the thermodynamics and reaction mechanisms involved in CO₂ hydrogenation to BTX and PX, revealing the key factors influencing product selectivity. The effects of catalyst modification methods, including silylation, silicalite encapsulation, core-shell structures, and metal modification, on the selectivity and activity of catalyst are discussed. Factors such as zeolite morphology, catalyst size, contact time, mesoporosity, acidity, and surface alkylation/methylation are analyzed for their effects on BTX and PX selectivity. Lastly, the paper outlines the current challenges and future perspectives in advancing CO₂ hydrogenation towards the production of BTX and PX, highlighting opportunities for further research and technological advancements in this area.