Ambient-pressure hydrogenation of CO2 into long-chain olefins

Abstract

The conversion of CO2 by renewable power-generated hydrogen is a promising approach to a sustainable production of long-chain olefins (C4+=) which are currently produced from petroleum resources. The decentralized small-scale electrolysis for hydrogen generation requires the operation of CO2 hydrogenation in ambient-pressure units to match the manufacturing scales and flexible on-demand production. Herein, we report a Cu-Fe catalyst which is operated under ambient pressure with comparable C4+= selectivity (66.9%) to that of the state-of-the-art catalysts (66.8%) optimized under high pressure (35 bar). The catalyst is composed of copper, iron oxides, and iron carbides. Iron oxides enable reverse-water-gas-shift to produce CO. The synergy of carbide path over iron carbides and CO insertion path over interfacial sites between copper and iron carbides leads to efficient C-C coupling into C4+=. This work contributes to the development of small-scale low-pressure devices for CO2 hydrogenation compatible with sustainable hydrogen production.

Nanostructured Materials for Photothermal Carbon Dioxide Hydrogenation: Regulating Solar Utilization and Catalytic Performance

“…We think that it is necessary to enhance the adsorption of intermediates on catalysts during CO 2 hydrogenation and enhance the C–C coupling capacity. Doping and multimetalization methods have been developed to enhance the C 2+ production from thermocatalytic CO 2 hydrogenation . These catalyst design strategies can also be applied to promote the C 2+ production selectivity of the photothermal catalytic CO 2 reduction.…”

Heterogeneous Catalysts toward CO2 Hydrogenation for Sustainable Carbon Cycle

“…Recent years have witnessed the breakthrough in hydrogenation of CO 2 into C 2+ hydrocarbons and oxygenates such as olefins, higher alcohols, gasoline, jet fuels, and aromatics. ,,, This process is rather challenging because of the high kinetic barriers for the formation of CC bonds, in other words, competition between CO activation, CC coupling, and CH bond formation. The mechanisms for C 2+ production generally involves two routes that are classified by the intermediates, as shown in Figure b.…”

“…Parallel to the methanol synthesis, great efforts have also been devoted to CO 2 methanation, which flourished for the use of coke oven gas in 1980s and was commercially operated recently . Recently, CO 2 has also been hydrogenated into long-chain products with high selectivity. , …”

“…9 Recently, CO 2 has also been hydrogenated into long-chain products with high selectivity. 10,11 In this Viewpoint, we discuss heterogeneous CO 2 hydrogenation from mechanistic perspectives, aiming to close the carbon cycle. Fundamental insights including descriptors and reaction mechanisms are overviewed to help the researchers design active and selective catalysts.…”

Synthesis of Alkene and Ethanol in CO2 Hydrogenation on a Highly Active Sputtering CuNaFe Catalyst

“…For the above chemicals, olefin and ethanol are both high-value intermediates or chemicals for modern society. The synthesis of olefin via CO 2 hydrogenation generally requires a tandem reaction of C–O activation, as well as subsequent C–C coupling. − The representative catalyst is composed of an oxides/zeolite composite with methanol as an intermediate, and an iron-based catalyst with CO as an intermediate. In comparison, producing ethanol is more challenging to achieve from CO 2 hydrogenation due to the complexity in various reaction pathways and the uncontrollability on C–O insertion in parallel with C–C coupling from untamed surface sites.…”