Electrocatalysis & Energy Conversion
·
Alkaline HER electrocatalyst economics
HER Catalyst
After 168 h at 500 mA/cm2 at 80 °C, does NiMo or in situ Co match Pt/C at 0.05, 0.15 or 0.50 mg Pt/cm2, and at what Pt loading is breakeven reached?
THE QUESTION
Which platinum-free composition holds HER overpotential below [threshold] at 500 mA/cm2 for [duration] in the target electrolyte, at catalyst cost per kW below the Pt reference? Verifier: 3-electrode screen then single-cell. [baseline: to verify]
WORK ORDER
Single-cell comparison of PGM-free alkaline HER cathodes against a platinum loading ladder at 500 mA/cm2
BACKGROUND
What this Apodex Lab is
Commercial alkaline water electrolysers split water to generate hydrogen, but their cathode electrodes rely on scarce noble metals such as platinum or on activated nickel. Replacing platinum with abundant transition metals like iron, nickel, or cobalt could expand electrolyser manufacturing, provided the alternatives do not forfeit electrical efficiency or degrade rapidly under industrial cell conditions.
Published claims that platinum-free catalysts can replace platinum rely almost entirely on low-current screenings. The strongest recent result reported an overpotential of 81 mV at only 10 mA/cm2 with a 14% current loss over 1000 minutes (~17 hours). That operating current is fifty times below the industrial current density of 500 mA/cm2, and the duration is orders of magnitude short of production lifetimes. Furthermore, platinum achieves high activity at low utilisation, meaning that low platinum loadings may beat base-metal candidates on cost per kilowatt. Published platinum baselines also scatter widely between laboratories, leaving the actual economic crossover unmeasured.
The HER Catalyst Apodex Lab evaluates whether platinum-free cathodes beat platinum in a harmonised zero-gap single cell held at 500 mA/cm2 in 30 wt% alkaline electrolyte at 80 °C for 168 h. The measurement tests electrodeposited NiMo, in situ deposited cobalt, and a commercial activated-nickel cathode directly against a reference ladder of platinum on nickel felt at 0.05, 0.15, and 0.50 mg Pt/cm2. By tracking overpotential gaps and degradation slopes with reference-electrode drift held under 5 mV, the protocol identifies the precise platinum loading where platinum stops being cheaper per kilowatt. This outcome gives electrolyser developers the empirical basis either to qualify a verified platinum-free cathode or to freeze stack specifications on an optimised platinum loading.
WHY NOW
Why the field is spending on an assumption
Published tests of platinum-free alkaline hydrogen-evolution cathodes rely on screening currents of 10 mA/cm2 held for tens of hours. These measurements do not show whether iron-, cobalt- or nickel-based catalysts survive industrial operation at 500 mA/cm2 in concentrated alkaline electrolyte at 80 °C. Furthermore, reported platinum reference potentials scatter across laboratories, preventing direct comparisons between independent studies. Although hundreds of non-precious compositions are published annually, patent filings continue to claim noble metals. With harmonised zero-gap single cells now demonstrated across eleven laboratories, running candidate cathodes alongside a platinum loading ladder on a single test stand determines whether low platinum loadings outperform non-precious alternatives under operating conditions.
WHAT WE’D BUY
What we would ask a laboratory to run
We are not buying the answer. We are buying a measurement with an interval — and the bars it will be compared against.
An electrochemistry test facility operates seven cathode formulations in 5 cm2 zero-gap single cells containing 30 wt% alkaline electrolyte at 80 °C, held at 500 mA/cm2 for 168 h. The run evaluates electrodeposited NiMo, in situ deposited Co, commercial activated nickel sheet, bare nickel felt, and platinum on carbon at 0.05, 0.15 and 0.50 mg Pt/cm2. For each non-platinum cathode, the laboratory measures the 168 h internal-resistance-corrected overpotential gap against each platinum loading, returning a 90% confidence interval with a half-width of at most 16 mV. The report also delivers the degradation slope in µV/h between 24 and 168 h and the interpolated platinum breakeven loading in mg/cm2.
SCOPE & LIMITS
The 5 cm2 single-cell format under-represents bubble accumulation and current maldistribution seen in full-scale stacks, meaning absolute overpotentials serve as lower bounds while relative differences between catalyst arms transfer.
WHO EXECUTES
The kind of lab that can run this
An electrochemistry contract laboratory or university core facility equipped with three-electrode alkaline cells, potentiostats, and a zero-gap alkaline water electrolysis single-cell test stand able to hold 500 mA/cm2 in 30 wt% KOH.
EXECUTOR KIND
wet-lab
WAYS IN
FOR PIs, LABS & CROs
Complete tasks no model can.
Paid per task, credited by name — a “Verified by” line for as long as the discovery it settled exists. You choose the work: browse the tasks above, respond to what you can actually run.
CREATE AN APODEX LAB
Have a question of your own?
Give it its own laboratory. Watch it decompose into an executable manifest.
ASK A FOLLOW-UP QUESTION
Push on our assumptions.
Every Apodex Lab lists what it doesn’t know. Good questions compound.
Every Apodex Lab shares the same verified-knowledge ledger. No laboratory works alone.