Research progress on directly converting CO ₂ into heavy hydrocarbons via heterogeneous catalysis is summarized and discussed.

Although considerable efforts have been made in converting carbon dioxide to hydrocarbons via hydrogenation processes, precise control of C–C coupling towards heavy olefins remains a challenge. Here we report a carbon dioxide hydrogenation to olefin process that achieves 72% selectivity for alkenes and 50.3% selectivity for C_4–18 alkenes, of which formation of linear α-olefins accounts for 80%. The process is catalyzed by carbon-supported iron, commonly used in C–C coupling reactions, with multiple alkali promoters extracted from corncob. The design is based on the synergistic catalysis of mineral elements in biomass enzyme on which carbon dioxide can be directly converted into carbohydrate. The mineral elements from corncob may promote the surface enrichment of potassium, suppressing the secondary hydrogenation of alkenes on active sites. Furthermore, carburization of iron species is enhanced to form more Fe₅C₂ species, promoting both the reverse water–gas shift reaction and subsequent C–C coupling.

Tuning CO₂ hydrogenation product distribution to obtain high-selectivity target products is of great significance. However, due to the imprecise regulation of chain propagation and hydrogenation reactions, the oriented synthesis of a single product is challenging. Herein, we report an approach to controlling multiple sites with graphene fence engineering that enables direct conversion of CO₂/H₂ mixtures into different types of hydrocarbons. Fe-Co active sites on the graphene fence surface present 50.1% light olefin selectivity, while the spatial Fe-Co nanoparticles separated by graphene fences achieve liquefied petroleum gas of 43.6%. With the assistance of graphene fences, iron carbides and metallic cobalt can efficiently regulate C-C coupling and olefin secondary hydrogenation reactions to achieve product-selective switching between light olefins and liquefied petroleum gas. Furthermore, it also creates a precedent for CO₂ direct hydrogenation to liquefied petroleum gas via a Fischer-Tropsch pathway with the highest space-time yields compared to other reported composite catalysts.

CO₂/H₂ mixtures can be directly converted into long-chain hydrocarbons with a yield of 26.7% over a bimetallic FeCo catalyst via strengthening the reinforced chain growth reaction.

A series of spinel-like catalysts (ZnFe₂O₄) are tailor-made synthesized through a solvent-thermal synthesis for CO₂ hydrogenation.