Tailoring the CO2 Hydrogenation Performance of Fe-Based Catalyst via Unique Confinement Effect of the Carbon Shell

Graphical Core-shell structured Fe-based catalyst Na−Fe 3 O 4 @C with confinement effect delivered higher productivity of light olefins compared with the naked Na−Fe 2 O 3 counterpart. Multiple characterization and DFT calculation verified that the timely carbon chain-growth termination, as well as unique CO 2 /H 2 ratio and electronic property on the catalytic interface played vital roles in boosting light olefins synthesis. Even though Fe-based catalysts have been widely employed for CO 2 hydrogenation into hydrocarbons, oxygenates, liquid fuels, etc., the precise regulation of their physicochemical properties is needed to enhance the catalytic performance. Herein, under the guidance of the traditional concept in heterogeneous catalysis-confinement effect, a core-shell structured catalyst Na−Fe 3 O 4 @C is constructed to boost the CO 2 hydrogenation performance. Benefiting from the carbon-chain growth limitation, tailorable H 2 /CO 2 ratio on the catalytic interface, and unique electronic property that all endowed by the confinement effect, the selectivity and space-time yield of light olefins (C 2 = −C 4 = ) are as high as 47.4 % and 15.9 g mol Fe −1 h −1 , respectively, which are all notably higher than that from the shell-less counterpart. The function mechanism of the confinement effect in Fe-based catalysts are clarified in detail by multiple characterization and density functional theory (DFT). This work may offer a new prospect for the rational design of CO 2 hydrogenation catalyst.