CO₂ Hydrogenation to Higher Alcohols over K-Promoted Bimetallic Fe–In Catalysts on a Ce–ZrO₂ Support

Abstract

Novel K-promoted bimetallic Fe-and In-based catalysts on a Ce− ZrO 2 support were prepared and tested for higher alcohol synthesis from CO 2 and hydrogen. The FeIn/Ce−ZrO 2 precursors with different Fe contents were characterized in detail, and well-dispersed Fe 2 O 3 and In 2 O 3 phases with oxygen vacancies were observed. The catalysts were tested in a continuous setup at extended times on stream (up to 100 h) at 300 °C, 10 MPa, a gas hourly space velocity of 4500 mL g −1 h −1 , and a H 2 /CO 2 ratio of 3. The effect of K loading, the pretreatment atmosphere, Fe/(Fe + In) molar ratios, and calcination temperature on CO 2 conversion and product selectivity were studied. Best performance with a CO 2 conversion of 29.6% and a higher alcohol selectivity of 28.7%, together with good stability, was obtained over a K-0.82-FeIn/Ce−ZrO 2 _900 catalyst after activation under a CO atmosphere. These findings were rationalized by considering the effects of the individual catalyst components (K, Fe, and In) on catalyst performance. Surprisingly, the presence of calcined SiC, used as a diluent in the packed bed reactor, was shown to have a positive effect on catalyst performance and as such also is catalytically active. The best performance in terms of higher alcohol yield (8.5%) obtained in this work ranks in the top three of reports on CO 2 hydrogenation to higher alcohols in a continuous setup. Moreover, light olefins with 20.3% selectivity (6.0% yield) were coproduced over the optimized catalyst, which has a positive effect on the economic potential of the catalysts.

The structure-activity interactions of Cu/Zn, In/Pd and Fe/K catalysts supported on mesoporous SBA-15; CO2 Hydrogenation at Low Pressure

“…The most effective/promising catalytic systems for CO 2 hydrogenation to methanol reported in the literature are copper-zinc oxide based catalysts, indium oxide-palladium based catalysts [2] and ironpotassium based catalysts [3]. The complexity of the multi-component catalytic systems and challenges in elucidating the active sites are the main stumbling blocks in developing rational catalyst design strategies [2].…”

Thermodynamic Analysis of CO2 Hydrogenation to Higher Alcohols (C2–4OH): Effects of Isomers and Methane

“…Converting CO 2 to fuels such as methane, higher hydrocarbons, methanol, and higher alcohols (C 2–4 OH) has attracted considerable interest in recent years. − Among them, higher alcohols possessing a high volumetric energy density, a relatively high octane/cetane number, and low vapor pressure are promising alternatives for gasoline and diesel. , Ethanol, 1-propanol, 2-propanol, 1-butanol, and isobutanol have been reported as alternative fuels in a gasoline/diesel engine. − The higher alcohols can be blended with gasoline/diesel or can be used alone, and their content varies from below 0.05 to 1. Depending on the nature of the higher alcohol and its content, the engine can be used directly or after modifications.…”

“…Even though hydrogenation of CO 2 to higher alcohols has been extensively studied for years focusing on thermodynamic analysis as well as the design and development of highly active catalysts, ,,,, its commercial application is still absent due to the low selectivity to higher alcohols. Generally, the hydrogenation of CO 2 in the gas phase possesses a low selectivity to higher alcohols with ethanol as the main higher alcohol .…”

“…18 In addition, ED95, a bioethanol fuel for heavy diesel vehicles provided by SEKAB, containing ethanol (0.95) and an ignition improver (0.05), has been successfully used in modified diesel engines. 16,17 Even though hydrogenation of CO 2 to higher alcohols has been extensively studied for years focusing on thermodynamic analysis as well as the design and development of highly active catalysts, 10,11,13,27,28 its commercial application is still absent due to the low selectivity to higher alcohols. Generally, the hydrogenation of CO 2 in the gas phase possesses a low selectivity to higher alcohols with ethanol as the main higher alcohol.…”

Estudo de catalisadores do tipo Ni-Ga para a síntese de metanol a partir da hidrogenação do CO>sub<2>/sub< em baixas pressões

“…Esses efeitos começaram a ser notados na década de , 2013). Portanto, qualquer progresso no uso de CO2 como um reagente útil só surgirá através do uso de catalisadores eficientes (XI et al, 2021). Na Figura 3 estão ilustrados os principais produtos obtidos através de reações de hidrogenação do CO2, indicando também os seus principais catalisadores e as entalpias de formação para cada produto.…”