Platinum hydride formation during cathodic corrosion in aqueous solutions
Thomas J P Hersbach1,2, Angel T Garcia-Esparza2, Selwyn Hanselman1
1Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands.
Nature Materials
|January 22, 2025
Summary
Researchers observed elusive platinum hydride intermediates during cathodic corrosion using X-ray absorption spectroscopy. This finding resolves a long-standing debate about the mechanism of metal etching at negative potentials.
Area of Science:
- Electrochemistry
- Materials Science
- Surface Chemistry
Background:
- Cathodic corrosion is an electrochemical process affecting metals at negative potentials.
- The mechanism involves a suspected metal-containing anion intermediate, yet to be directly observed.
- Understanding this intermediate is crucial for controlling metal degradation.
Purpose of the Study:
- To provide direct evidence for the existence of intermediate species during cathodic corrosion.
- To resolve the long-standing debate regarding the mechanism of cathodic corrosion.
- To identify the elusive intermediate responsible for metal etching.
Main Methods:
- Utilized high-energy-resolution X-ray absorption near-edge structure (XANES) spectroscopy.
- Investigated platinum nanoparticles undergoing cathodic corrosion in 10 mol/L NaOH.
- Employed first-principles simulations to interpret experimental spectroscopic data.
Main Results:
- Detected subtle chemical changes in platinum nanoparticles during corrosion.
- Observed spectral features matching simulations of surface platinum multilayer hydrides.
- Provided direct spectroscopic evidence for hydride-like platinum intermediates.
Conclusions:
- The study supports the existence of hydride-like platinum species during cathodic corrosion.
- These unstable intermediates were observed despite interfering hydrogen bubble formation.
- The identified intermediate clarifies the fundamental mechanism of cathodic corrosion.
Related Concept Videos
01:08Electrodeposition
581
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...
581
03:45Formation of Complex Ions
23.2K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
23.2K
02:49Corrosion
23.7K
The degradation of metals due to natural electrochemical processes is known as corrosion. Rust formation on iron, tarnishing of silver, and the blue-green patina that develops on copper are examples of corrosion. Corrosion involves the oxidation of metals. Sometimes it is protective, such as the oxidation of copper or aluminum, wherein a protective layer of metal oxide or its derivatives forms on the surface, protecting the underlying metal from further oxidation. In other cases, corrosion is...
23.7K
01:26Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
1.8K
Radical substitution reactions can be used to remove functional groups from molecules. The hydrogenolysis of alkyl halides is one such reaction, where the weak Sn–H bond in tributyltin hydride reacts with alkyl halides to form alkanes. Here, the reagent Bu3SnH yields tributyltin halide as a byproduct.
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation...
1.8K
01:01Acid Halides to Carboxylic Acids: Hydrolysis
2.5K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
2.5K
01:10Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism
3.0K
Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
3.0K