Related Experiment Video
Updated: Jun 10, 2026
09:02
Synthesis of Platinum-nickel Nanowires and Optimization for Oxygen Reduction Performance
Published on: April 27, 2018
O2 reduction by lithium on Au(111) and Pt(111)
1Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. xuy2@ornl.gov
The Journal of Chemical Physics
|July 17, 2010
Summary
This study reveals that lithium-oxygen (Li-ORR) cathode performance is limited by surface chemistry. Gold (Au) surfaces are more effective for Li-ORR than platinum (Pt) surfaces due to differences in oxygen reduction pathways and product stability.
Area of Science:
- Electrochemistry
- Materials Science
- Computational Chemistry
Background:
- Lithium-oxygen (Li-O2) batteries offer high specific energy for portable power.
- Understanding the Li-O2 oxygen reduction reaction (Li-ORR) is crucial for improving battery efficiency.
- Current knowledge of Li-ORR mechanistic details and limiting factors is scarce.
Purpose of the Study:
- To investigate the fundamental surface chemistry of Li-ORR on metal surfaces.
- To elucidate the factors influencing discharge and charge efficiencies in Li-O2 cathodes.
- To compare the Li-ORR activity of Au(111) and Pt(111) surfaces.
Main Methods:
- Periodic density functional theory (DFT) calculations.
- Thermodynamic modeling.
- Analysis of O2 reduction pathways on Au(111) and Pt(111) surfaces.
Main Results:
- On Au(111), O2 reduction initially forms superoxide (LiO2) with a low reversible potential (1.51 V).
- On Pt(111), O2 reduction favors dissociative adsorption, with atomic O reduction at 1.97 V.
- O2 lithiation on both surfaces weakens the O-O bond, favoring monoxide (Li(x)O) formation over peroxide (Li(x)O2).
- Li(x)O species aggregate, and their interfaces with metal surfaces are active sites for LiO2 formation/dissociation.
- Bulk Li2O is the most stable phase up to 2.59 V.
- Discharge initiates with reduction of chemisorbed atomic O, occurring at 2.42 V on Au(111) and limited to 1.97 V on Pt(111) due to O stability.
Conclusions:
- The intrinsic reactivity of Pt(111) makes it less effective for Li-ORR compared to Au(111).
- Surface chemistry and product stability significantly impact Li-ORR efficiency.
- Understanding these surface interactions is key to designing advanced Li-O2 batteries.
Related Concept Videos
01:19Acid Halides to Alcohols: LiAlH4 Reduction
Acid halides are reduced to alcohols in the presence of a strong reducing agent like lithium aluminum hydride.
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
01:20Amides to Amines: LiAlH4 Reduction
Amide reduction with strong reducing agents like lithium aluminum hydride proceeds through a nucleophilic acyl substitution to form amines. Primary, secondary, and tertiary amides yield primary, secondary, and tertiary amines, respectively.
Amide reduction requires two equivalents of the reducing agent, acting as a source of hydride ions. As shown in the figure, the reaction is initiated with a nucleophilic attack by the hydride ion at the carbonyl carbon to form a tetrahedral intermediate.
Amide reduction requires two equivalents of the reducing agent, acting as a source of hydride ions. As shown in the figure, the reaction is initiated with a nucleophilic attack by the hydride ion at the carbonyl carbon to form a tetrahedral intermediate.
02:23Alcohols from Carbonyl Compounds: Reduction
Reduction is a simple strategy to convert a carbonyl group to a hydroxyl group. The three major pathways to reduce carbonyls to alcohols are catalytic hydrogenation, hydride reduction, and borane reduction.
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...
00:55Nitriles to Amines: LiAlH4 Reduction
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
01:17Esters to Alcohols: Hydride Reductions
Esters are reduced to primary alcohols when treated with a strong reducing agent like lithium aluminum hydride. The reaction requires two equivalents of the reducing agent and proceeds via an aldehyde intermediate.
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...