Related Experiment Video
Updated: Apr 23, 2026
09:21
Tuning the Acidity of Pt/ CNTs Catalysts for Hydrodeoxygenation of Diphenyl Ether
Published on: August 17, 2019
7.3K
Tuning Proton Activity in Organic Electrolytes for Selective CO2-to-Long-Chain Hydrocarbon Conversion.
Xiangyun Ma1, Yingqing Ou1, Boon Siang Yeo1
1Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Journal of the American Chemical Society
|April 22, 2026
Summary
Tuning proton donor acidity in dimethyl sulfoxide (DMSO) electrolytes enhances carbon dioxide (CO2) reduction to hydrocarbons (HCs). This method optimizes selectivity for carbon-neutral fuels by controlling proton activity and suppressing hydrogen gas formation.
Area of Science:
- Electrochemistry
- Catalysis
- Renewable Energy
Background:
- Electrochemical reduction of carbon dioxide (CO2) to hydrocarbons (HCs) offers a route to carbon-neutral liquid fuels.
- Nickel-based catalysts show promise but often suffer from competing hydrogen gas (H2) production.
- Controlling proton activity is crucial for selective CO2 conversion.
Purpose of the Study:
- To systematically tune proton activity in aprotic dimethyl sulfoxide (DMSO) electrolytes for CO2 reduction.
- To investigate the effect of alcohol proton donors on hydrocarbon selectivity.
- To optimize conditions for maximizing CO2-to-HC conversion efficiency.
Main Methods:
- Systematic variation of alcohol proton donor acidity in DMSO electrolyte.
- Electrochemical reduction of CO2 using nickel-based catalysts.
- Nuclear magnetic resonance (NMR) spectroscopy to analyze solvation structure and proton donor behavior.
Main Results:
- Hydrocarbon selectivity showed a volcano-shaped dependence on proton donor acidity.
- Faradaic efficiency for C1-C6 HCs increased from 4.0% to 22.1% with ethylene glycol (EG) in DMSO.
- Specific solvation of EG in DMSO at 0.2 M concentration facilitated CO2 activation and C-C chain growth while suppressing H2 formation.
Conclusions:
- Tuning proton donor molecular structure and concentration-dependent solvation in DMSO is key to maximizing CO2-to-HC conversion.
- A moderate proton-activity window, achieved through controlled solvation, enhances selectivity for hydrocarbon fuels.
- This strategy offers a pathway to efficient synthesis of carbon-neutral liquid fuels from CO2.
Related Concept Videos
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
7.9K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
7.9K
01:10α-Alkylation of Ketones via Enolate Ions
2.2K
Ketones with α protons are deprotonated by strong bases like lithium diisopropylamide (LDA) to form enolate ions. The anion is stabilized by resonance, and its hybrid structure exhibits negative charges on the carbonyl oxygen and the α carbon. This ambident nucleophile can attack an electrophile via two possible sites: the carbonyl oxygen, known as O-attack, or the α carbon, known as C-attack. The nucleophilic attack via the carbanionic site is preferred. This is due to the...
2.2K
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
13.8K
If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...
13.8K
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
3.1K
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an...
3.1K
01:33Regioselective Formation of Enolates
2.6K
As depicted in the figure below, the unsymmetrical ketones can form two possible enolates: less substituted or more substituted enolates. Usually, the thermodynamic enolates are formed from the more substituted α-carbon atom, while the kinetic enolates are formed faster by deprotonation from the less substituted position. The thermodynamic enolates have lower energy, so they are more stable. But the energy required to form kinetic enolates is less.
2.6K
02:13Reduction of Alkenes: Catalytic Hydrogenation
12.2K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
12.2K