A Unique Cation Leaching-Triggered Molecular Aggregate for Water Oxidation in Acidic Condition
19 October 2026
Affiliation
NTU
Focus topic
Low-carbon H2 & Derivatives
More hydrogen from less iridium in PEM electrolyzers
Summary
A mesoporous, support-free iridium oxyhydroxide catalyst for the oxygen evolution reaction (OER), the efficiency-limiting half of water splitting, for use as the anode of PEM water electrolyzers.
Achievements: in a 5 cm2 PEM electrolyzer at 80oC, cell voltage at 1 A cm-2 fell to 1.54 V, versus 1.81 V for commercial rutile IrO2 and 1.57 V for a commercial amorphous iridium benchmark, with a further ~190 mV overpotential reduction at 4 A cm-2. Performance surpasses the US DOE 2026 technical targets for PEM electrolyzers and approaches the 2031 target. It showed the highest mass activity among the benchmarked iridium catalysts (130 vs 80 A per g Ir at 1.5 V against a comparative catalyst). It ran at 1 A cm-2 for ~400 h and through 7 cycles of a simulated solar power profile, with a projected lifetime of ~38,000 +/- 11,000 h. Being support-free avoids support corrosion, and iridium dissolved during synthesis can be recycled.
Carbon abatement: lowers the energy and iridium cost of green hydrogen from renewable electricity, helping PEM electrolysis scale.
What makes this novel compared to best-in-class technology?
Conventional nano-iridium catalysts need toxic solvents, low-yield synthesis and supports that degrade. This support-free, hierarchically porous catalyst is made by a simple, scalable route, delivers more activity per gram of iridium and beats US DOE 2026 PEM electrolyzer targets.
TRL Level
1-3
Relevant for
PEM electrolyzer and stack manufacturers
Catalyst and MEA suppliers
Green hydrogen producers co-located with solar/wind
Power-to-gas energy storage operators
About
Inventors: Chen Yubo, Xu Zhichuan, Adrian Charles Fisher
Affiliation: Nanyang Technological University, Singapore (NTU), School of Materials Science and Engineering (MSE); University of Cambridge
Contact NTU for licensing opportunities and more information.
Please quote ID ref [2023-085] in your email.