Electrocatalytic Reactions in Alkaline Media

Electrocatalytic reactions in alkaline media underpin a range of sustainable energy technologies, notably water electrolysis and alkaline fuel cells. In these systems, the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR) occur under basic electrolyte conditions, offering advantages such as improved catalyst utilisation and the adoption of earth-abundant metals. However, alkaline environments impose kinetic barriers, including sluggish water dissociation and hydroxide-mediated proton transfer, which have driven the design of specialised electrocatalysts. Current strategies focus on optimising electronic structures through alloying, interface engineering to promote reactant adsorption and charge transfer, and nanostructuring to increase active site density. Success in this domain promises to reduce reliance on scarce noble metals, lower system costs and enable large-scale hydrogen production and usage, thereby advancing the global shift towards a low-carbon energy infrastructure.

Research from Nature Portfolio

Recent studies have introduced a quantum well-like catalytic structure in which nickel nanoparticles are atomically confined within a carbon-doped molybdenum oxide heterojunction. This architecture selectively channels electrons from hydrogen oxidation while suppressing self-oxidation of nickel, yielding high power outputs and robust durability in anion-exchange membrane fuel cells. Complementing this advance, a tetragonal nickel–molybdenum nanoalloy (MoNi₄) has demonstrated exceptional HOR activity in alkaline electrolytes, surpassing platinum benchmarks in exchange current density and exhibiting tolerance to carbon monoxide. Together, these works illustrate how precise control of alloy composition and interfacial electronic effects can overcome the inherent kinetic challenges of hydrogen electrochemistry in alkaline environments.

Electrocatalytic Reactions in Alkaline Media publication trend

The graph below shows the total number of articles in electrocatalytic reactions in alkaline media across all publications each year (not limited to Nature Index journals).

Technical terms

Alkaline media: An aqueous electrolyte with pH greater than 7, typically containing hydroxide ions.

Electrocatalyst: A material that accelerates the rate of an electrochemical reaction at an electrode surface.

Hydrogen evolution reaction (HER): The reduction process in which water molecules or hydroxide ions are converted to hydrogen gas at the cathode.

Hydrogen oxidation reaction (HOR): The oxidation process in which hydrogen gas releases electrons and forms hydroxide ions at the anode.

Overpotential: The extra potential beyond the thermodynamic requirement needed to drive an electrochemical reaction at a specified rate.

Exchange current density: A measure of intrinsic electrocatalytic activity, defined as the current density at equilibrium potential.

References

1. Quantum confinement-induced anti-electrooxidation of metallic nickel electrocatalysts for hydrogen oxidation. Nature Energy (2024).
2. Activating Ru in the pyramidal sites of Ru2P‐type structures with earth‐abundant transition metals for achieving extremely high HER activity while minimizing noble metal content. Carbon Energy (2024).
3. Exceptional Electrochemical HER Performance with Enhanced Electron Transfer between Ru Nanoparticles and Single Atoms Dispersed on a Carbon Substrate. Angewandte Chemie International Edition (2021).