Vanadium “Molecular Switch” Catalyst Points to New Path for Green Hydrogen in Harsh Acidic Electrolyzers
Date: 01 Jan 2026 |
A research team at the Singular Centre for Research in Biological Chemistry and Molecular Materials (CiQUS), led by María Giménez-López, has reported a major advance in catalyst design for water electrolysis under strongly acidic conditions, a regime typically dominated by precious metals such as iridium and platinum. Their study demonstrates that a vanadium-based molecular cluster integrated with carbon nanotubes can act as a catalytic “switch,” changing function depending on how the hybrid material is assembled.
Vanadium at the core: a stable, reversible electron reservoir
At the heart of the discovery is a vanadium cluster (polyoxometalate) combined with carbon nanotubes. In both operational modes, the vanadium cluster serves as a stable and reversible electron reservoir, supporting catalytic activity while the surrounding molecular environment determines whether the system favours oxygen evolution (OER) or hydrogen evolution (HER).
The “switch” is architectural—not compositional
Crucially, the catalytic toggle does not require changing the chemical composition. Instead, it depends on how TRIS⁺ organic cations around the vanadium cluster are arranged:
- Physically mixed configuration: TRIS⁺ cations remain locked in the crystal structure, steering the reaction toward oxygen production via a distinct oxidation pathway.
- Directed assembly configuration: TRIS⁺ cations become exposed at the surface and act as a “proton sponge,”shifting the system into an exceptional hydrogen-producing catalyst.
Performance benchmarked against precious metals
Electrochemical data reported in the study indicate that, in its oxygen-producing configuration, the material rivals commercial iridium catalysts, while in its hydrogen-producing configuration, its efficiency approaches platinum, the benchmark for HER.
Why this matters
Hydrogen production through water electrolysis is central to the clean-energy transition, but durable, high-performance catalysts in acidic media remain a cost and supply-chain challenge. This work introduces a new paradigm: programming catalytic reactivity by controlling assembly and microenvironment, potentially enabling multifunctional, durable, Earth-abundant catalyst systems for future electrolysers.
Publication
The research is published in Advanced Materials: “POM-Based Water Splitting Catalyst Under Acid Conditions Driven by Its Assembly on Carbon Nanotubes” (Eugenia P. Quirós-Díez et al.), DOI: 10.1002/adma.202512902.