Ionic Liquids as homogeneous photocatalyst for CO2 reduction in protic solvents

Peng, Yulan; Szeto, Kaï C.; Santini, Catherine C.; Danièle, S.

doi:10.1016/j.ceja.2022.100379

“…Peng et al and Qadir et al reported CO formation via the direct photoexcitation of imidazolium-based ionic liquids. [22,23] For this reason, the photocatalytic activity was also studied in the absence of [Ru(bpy) 3 ](PF 6 ) 2 and [Re(bpy)(CO) 3 ]Cl; however, the formation of CO was not observed under otherwise similar conditions. This observation is in accordance with UV-vis spectroscopy data of ionic liquid and catalyst (ESI Figure S8), indicating that absorption of the ionic liquid is very low in comparison to the catalyst at the chosen conditions.…”

Section: Resultsmentioning

confidence: 99%

“…and Qadir et al. reported CO formation via the direct photoexcitation of imidazolium‐based ionic liquids [22,23] . For this reason, the photocatalytic activity was also studied in the absence of [Ru(bpy) 3 ](PF 6 ) 2 and [Re(bpy)(CO) 3 ]Cl; however, the formation of CO was not observed under otherwise similar conditions.…”

Section: Resultsmentioning

confidence: 99%

“…[15,22] However, as reported by Daniele et al, this mechanism is highly dependent on the pH value, since a HCO 3 À driven reaction is competing. [23] The synergistic role of ionic liquids as co-catalysts for photocatalytic CO 2 reduction via formation of the imidazolium-CO 2 adduct was also demonstrated in aprotic solvents. Different imidazolium-based ionic liquids were added to the photocatalytic tandem system [Ru(bpy) 3 ]Cl 2 /CoCl 2 • 6 H 2 O in different co-solvents by Lin et al [24] The best results were observed for a mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate ([C 2 mim]BF 4 ) with acetonitrile in a ratio of 75 % (v/v), resulting in an almost 3-fold increase in the reaction rate.…”

Section: Introductionmentioning

confidence: 96%

“…In case of suitable absorption properties, radical species are formed by homolytic cleavage of the imidazolium‐CO 2 adduct even in the absence of an external photosensitizer, thus forming CO 2 − ⋅ and imidazolium + ⋅ radicals in aqueous media [15,22] . However, as reported by Daniele et al., this mechanism is highly dependent on the pH value, since a HCO 3 − driven reaction is competing [23] …”

Section: Introductionmentioning

confidence: 97%

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Boosting Visible‐Light Carbon Dioxide Reduction with Imidazolium‐Based Ionic Liquids

Eisele,

Chaikhan,

Batool

et al. 2024

ChemCatChem

1

0

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Efficiently generating C1 building blocks from environmentally friendly carbon sources, such as through photocatalytic CO2 reduction, is essential for fostering a sustainable circular economy. The pursuit of gentle catalytic activation methods has yielded powerful catalysts that can be synergistically employed alongside various reaction media to enhance overall performance. Herein, we elucidate the influence of diverse imidazolium‐based ionic liquids as additives for visible‐light‐driven CO2reduction with ruthenium(II)‐ and rhenium(I)‐bipyridine complexes. Our investigation reveals that incorporating ionic liquids into traditional solvents at concentrations below 10% can markedly boost CO production while suppressing H2 generation. The best results were obtained for the highly basic ionic liquid [C2mim][OAc], resulting in a substantial rise in CO formation from 0.3 µmol/h to 5.4 µmol/h and an increase in turnover number from 3 to 59. This study underscores the cooperative influence of imidazolium‐based ionic liquids on CO2 photoreduction while circumventing their use as primary solvents, thus offering a promising avenue for sustainable chemical synthesis.

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“…Peng et al explored the connection between CO 2 photoreduction efficiency, UV/Vis adsorption capacity, and Kamlet-Taft (K-T) β-parameter values of the BMIm•OAc IL in water and isopropyl alcohol. [110] It was perceived that the CO 2 activation was related to the nature of the anion that drove the generation of the CO 2 *À reactive intermediate. It is also observed that the pH of the IL significantly promotes the CO 2 photoreduction.…”

Section: Photoreduction Of Co 2 By Ilsmentioning

confidence: 99%

Thermo‐ and Photocatalytic Activation of CO₂ in Ionic Liquids Nanodomains

Qadir

¹

,

Dupont

²

2023

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Ionic liquids (ILs) are considered to be potential material devices for CO 2 capturing and conversion to energyadducts. They form a cage (confined-space) around the catalyst providing an ionic nano-container environment which serves as physical-chemical barrier that selectively controls the diffusion of reactants, intermediates, and products to the catalytic active sites via their hydrophobicity and contact ion pairs. Hence, the electronic properties of the catalysts in ILs can be tuned by the proper choice of the IL-cations and anions that strongly influence the residence time/diffusion of the reactants, intermediates, and products in the nano-environment. On the other hand, ILs provide driving force towards photocatalytic redox process to increase the CO 2 photoreduction. By combining ILs with the semiconductor, unique solid semiconductor-liquid commodities are generated that can lower the CO 2 activation energy barrier by modulating the electronic properties of the semiconductor surface. This mini-review provides a brief overview of the recent advances in IL assisted thermal conversion of CO 2 to hydrocarbons, formic acid, methanol, dimethyl carbonate, and cyclic carbonates as well as its photo-conversion to solar fuels.

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Thermo‐ and Photocatalytic Activation of CO₂ in Ionic Liquids Nanodomains

Qadir

¹

,

Dupont

²

2023

View full text Add to dashboard Cite

Ionic liquids (ILs) are considered to be potential material devices for CO 2 capturing and conversion to energyadducts. They form a cage (confined-space) around the catalyst providing an ionic nano-container environment which serves as physical-chemical barrier that selectively controls the diffusion of reactants, intermediates, and products to the catalytic active sites via their hydrophobicity and contact ion pairs. Hence, the electronic properties of the catalysts in ILs can be tuned by the proper choice of the IL-cations and anions that strongly influence the residence time/diffusion of the reactants, intermediates, and products in the nano-environment. On the other hand, ILs provide driving force towards photocatalytic redox process to increase the CO 2 photoreduction. By combining ILs with the semiconductor, unique solid semiconductor-liquid commodities are generated that can lower the CO 2 activation energy barrier by modulating the electronic properties of the semiconductor surface. This mini-review provides a brief overview of the recent advances in IL assisted thermal conversion of CO 2 to hydrocarbons, formic acid, methanol, dimethyl carbonate, and cyclic carbonates as well as its photo-conversion to solar fuels.

show abstract

Ionic Liquids as homogeneous photocatalyst for CO2 reduction in protic solvents

Cited by 7 publications

References 49 publications

Boosting Visible‐Light Carbon Dioxide Reduction with Imidazolium‐Based Ionic Liquids

Boosting Visible‐Light Carbon Dioxide Reduction with Imidazolium‐Based Ionic Liquids

Thermo‐ and Photocatalytic Activation of CO₂ in Ionic Liquids Nanodomains

Thermo‐ and Photocatalytic Activation of CO₂ in Ionic Liquids Nanodomains

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Ionic Liquids as homogeneous photocatalyst for CO2 reduction in protic solvents

Cited by 7 publications

References 49 publications

Boosting Visible‐Light Carbon Dioxide Reduction with Imidazolium‐Based Ionic Liquids

Boosting Visible‐Light Carbon Dioxide Reduction with Imidazolium‐Based Ionic Liquids

Thermo‐ and Photocatalytic Activation of CO2 in Ionic Liquids Nanodomains

Thermo‐ and Photocatalytic Activation of CO2 in Ionic Liquids Nanodomains

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Product

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Thermo‐ and Photocatalytic Activation of CO₂ in Ionic Liquids Nanodomains

Thermo‐ and Photocatalytic Activation of CO₂ in Ionic Liquids Nanodomains