Technology for lower hydrogen cost

Beyond a single performance record.
We engineer lower clean hydrogen costs.

In anion exchange membrane (AEM) water electrolysis we engineer electrodes, MEAs, cells, electrolyser stacks and operating systems together to balance performance, durability, stack cost and manufacturability.

23 CELL · FULL STACKHydroXpand HXS-2 23-cell AEM electrolyzer stack
AVAILABLE · 23-CELL STACKHXS-2
ELECTRODE → MEA → CELL → STACK → SYSTEM
01 · HIGHER EFFICIENCY02 · LONGER DURABILITY03 · LOWER STACK COST04 · GREATER MANUFACTURABILITY
What is AEM

Anion exchange membrane electrolysis

Anion exchange membrane (AEM) electrolysis uses a solid polymer membrane in an alkaline environment. The membrane carries hydroxide ions (OH⁻), so the anode runs on nickel and iron based catalysts instead of iridium or other platinum group metals.

Alkaline electrolysis (AWE) uses a liquid electrolyte and a porous diaphragm: cheap materials, slow load response. PEM uses an acidic membrane: high performance, heavy precious metal dependence. AEM targets the ground between them, and HydroXpand manufactures the electrodes, stacks and systems for it.

From electrode to system

We engineer from electrode
through the operating system

To carry electrode performance into cells, stacks and real operation, we develop the membrane-electrode interface, flow paths, stack structure, electrolyte temperature and flow together. Results from each stage inform the next design.

  1. 01ELECTRODE

    HXP-an · HXP-ca

    Catalyst composition · electrode manufacturing

    NiFe-LDH · Pt/C · PtRu/C
  2. 02MEA · CELL

    Membrane-electrode interface

    Flow paths · compression · mass transfer

    Cell-level performance checks
  3. 03STACK

    HXS-2 · HXS-30

    Cell uniformity · sealing · thermal management

    Short-stack · full-stack validation
  4. 04SYSTEM

    HXB-V1

    Voltage · current · electrolyte temperature · flow

    Control under operating conditions

MEASURE→REVIEW→REDESIGNTest results from each stage inform the next design.

Measured on HXS-2

Performance and durability measured
on the HXS-2 available today

The default view shows the representative results needed for an initial decision. Expand the section below for public charts and detailed test conditions.

PERFORMANCE1.675V/cell @ 50 A

HXS-2 · 23-cell full stack
0.3 M KOH · 60 °C

DURABILITY2,400h+ continuous

HXS-2 · 23-cell full stack
0.3 M KOH · 40 °C · 50 A

View all charts and test conditions3 public datasets
SAME AREA, MORE OUTPUT

Track degradation as output increases

Separate short-stack runs at 50 A and 80 A were each tracked for approximately 1,000 hours at the same electrode area.

50 A
0.633 A/cm²88.9 µV/h
80 A
1.013 A/cm²93.9 µV/h
PUBLISHED i-V DATASET · 2026.04

Polarization curve (i-V)

1.675V/cell
HXS-2 23-cell full stack · 0.3 M KOH · 60 °C

Measured in April 2026. Rated at 50 A and 38.5 V across the stack; current density is referenced to the 79 cm² cathode area. This public curve predates the latest representative rated point above.

DURABILITY

Galvanostatic durability

2,281h published window
HXS-2 23-cell stack voltage and hydrogen-in-oxygen tracked through 2,281 hours at a constant 50 A
Single uninterrupted run at ambient pressure · HXS-2, 23 cells · 0.3 M KOH · 40 °C · 50 A · 80.2 µV/h/cell full-run linear fit

The latest continuous-operation record for the HXS-2 stack exceeds 2,400 hours. This chart shows the published 2,281-hour window.

Results apply to the stated test conditions and are not a product-lifetime guarantee. Detailed raw data are available on request.

Measured scale-up

We do not simply scale up
a small-cell result

As active area and cell count grow, we retune flow, temperature, compression and sealing, then measure performance again.

  1. 01CELL · SHORT STACK

    HXS-0

    1–25 cm²

    Cell and short-stack evaluation

  2. 02COMMERCIAL STACK

    HXS-2

    23-cell full stack

    Available measured · 98/79 cm²

  3. 0330 kW SCALE

    HXS-30

    600 cm² anode · 46 cells

    Scaling up 500 h+ continuous on five cells · approx. 521 cm² reference active area

Each stage requires its own test conditions and validation data.

View the HXS-30 development scope
Technical review

Tell us your target output and operating conditions

Electrode and MEA evaluation, BoP integration, and stack or system deployment each require different inputs. Share your target production, current, pressure, purity and available equipment, and we will recommend the relevant product and confirm what test data can be provided.

Request technical reviewDatasheets · resources