CO₂‐Promoted Catalytic Process Forming Higher Alcohols with Tunable Nature at Record Productivity

Abstract

Converting syngas obtained from renewable or abundant feedstocks into higher alcohols (HA) is a potentially more sustainable route to these important chemicals and fuels than industrial technologies, but lacks a performing catalytic process to reach commercialization. Here, we show that moderate CO 2 amounts (R = CO 2 /(CO + CO 2 ) = 0.12) in the feed raise the HA productivity over copper-iron catalysts carried on carbon nanofibers and promoted by potassium to a 3-fold higher level than the state of the art. CO 2 promotes copper dispersion and thus the formation of activated CO species, as in traditional methanol synthesis. Still, since its vicinity to iron is boosted, CO insertion into growing hydrocarbon chains prevails on hydrogenation, translating positive effects to HA production. Cascade zeolite-catalyzed upgrading of methanol and olefins byproducts generates a breakthrough process forming 2.42 g HA h À 1 g cat À 1 , which is 4-times superior to the best systems, and tuning the HA nature based on the aluminosilicate topology.

Mechanistic Aspects of the Role of K Promotion on Cu–Fe-Based Catalysts for Higher Alcohol Synthesis from CO2 Hydrogenation

“…Among the various catalytic materials, the Cu–Fe-based catalyst is one of the low-cost and high-activity catalysts in HAS from syngas. − This catalyst has been reported to achieve stable operation for more than 1200 h in the pilot test of HAS . It is widely accepted that iron carbide (FeC x ) is active for dissociative CO adsorption and carbon chain growth, while metallic Cu is responsible for nondissociative CO adsorption and its insertion. , The synergistic effect between FeC x and Cu by forming FeC x –Cu interfaces benefits HAS. − Although Cu–Fe catalysts exhibit good HAS activity, a large number of hydrocarbons (HCs) are produced.…”

Efficient Promoters and Reaction Paths in the CO2 Hydrogenation to Light Olefins over Zirconia-Supported Iron Catalysts

“…5,6 Nevertheless, CO 2 chemical utilization is challenging, because of its thermodynamic stability, resulting in low conversion. 7 With sustainable hydrogen as the co-reagent, CO 2 can be hydrogenated 7 to methanol, 8−10 dimethyl ether, 11−14 formic acid, 15,16 higher alcohols, 17 liquid hydrocarbon fuels, 18,19 aromatics, 20 and light olefins. 7,21−24 The light olefin synthesis from CO 2 has attracted particular attention in recent years from both academia and companies, because ethylene, propylene, and butylenes are major building blocks in the chemical industry.…”

Strain-Enhanced Phase Transformation of Iron Oxide for Higher Alcohol Production from CO2

“…One of the solutions to curtail this adverse effect is to convert CO 2 to high-value-added chemicals and fuels. − Conversion of CO 2 to C 2+ hydrocarbons is an attractive approach since it not only reduces the increasing CO 2 levels but also decreases the reliance on fossil fuel-based resources. Recently, the conversion of CO 2 into liquid fuels has grabbed significant interest owing to the production of safe transportable liquid hydrocarbons and alcohols from CO 2 . − Conversion of CO 2 to higher alcohols (HAs) has immense significance because of their multitude of applications in the chemical industry. HAs are extensively used as solvents, fuels, and fuel additives. , HAs such as ethanol and isobutanol are used as fuel additives to enhance the octane number and combustion efficiency of the engines.…”