Hydrogen Selective Catalytic Reduction

Eliminate DEF.
Reduce NOx 90%+.
Generate ammonia on demand.

H2SCR™ replaces delivered DEF with on-demand ammonia synthesis at the point of use — cutting logistics, eliminating storage, and achieving NOx reductions equivalent to traditional SCR systems. CO₂-free when paired with green hydrogen.

Technology validated by Science Direct peer-reviewed research
Explore OEM Licensing See how it works

$40B/yr
DEF market H2SCR™ is positioned to disrupt
65M
Tonnes CO₂ reduction potential per year
90%+
DeNOx effectiveness maintained
0
DEF deliveries, tanks, or freeze issues required

The Case for H2SCR™

Traditional SCR has a supply chain problem.

Every conventional SCR system depends on a continuous external supply of DEF or bulk ammonia — creating ongoing cost, complexity, and risk that H2SCR™ eliminates entirely.

Traditional SCR — The Problem

  • Ongoing DEF purchasing costs
  • Transportation and delivery expenses
  • Storage tanks and containment requirements
  • Freeze protection and degradation issues
  • Supply chain vulnerability
  • Environmental and safety risks from bulk ammonia

H2SCR™ — The Solution

  • No DEF deliveries — ever
  • No DEF storage tanks or containment
  • No freeze protection required
  • No chemical degradation issues
  • Reduced operating costs at scale
  • On-demand ammonia generation, point-of-use
  • Improved emissions compliance

Process

Four steps. No DEF. Full NOx control.

H2SCR™ produces ammonia on site from hydrogen and nitrogen, then injects it into a conventional SCR catalyst — the same proven NOx chemistry, without the supply chain.

01

Hydrogen Production

Hydrogen is generated via electrolysis, reforming, biomass, or sourced from existing industrial supply.

02

Nitrogen Capture

Nitrogen is extracted from ambient air or existing industrial gas systems — no cryogenic storage needed.

03

Ammonia Synthesis

H₂ and N₂ are catalytically combined on demand at the point of use. No DEF, no bulk ammonia, no logistics.

04

NOx Reduction

Ammonia is injected into the SCR catalyst, converting NOx to clean nitrogen and water vapor — 90%+ efficiency.


Target Markets

Any application that currently uses SCR or DEF.

H2SCR™ is designed for integration into existing and new equipment wherever NOx control is required.

Stationary Generators

Data centers, hospitals, emergency backup, and industrial gensets — high operating hours, high DEF consumption.

🏭

Industrial Facilities

Cement plants, refineries, chemical plants, and manufacturing with continuous emissions obligations.

💧

Water & Utilities

Municipal wastewater treatment, pumping stations, and utility backup generation.

Marine Applications

Vessel engines facing tightening IMO NOx Tier III requirements and zero-tolerance port emissions zones.

🔋

Microgrids & CHP

Combined heat and power systems, microgrid operators, and distributed energy resources in regulated zones.

⛏️

Mining & Oil/Gas

Remote operations where DEF logistics are especially costly, complex, and supply-chain constrained.


Hydrogen Integration

Best H₂ pathways for H2SCR™.

H2SCR™ is hydrogen-source agnostic. The four most commercially attractive pathways for stationary applications are below.

Recommended

Steam Reforming of Existing Fuel

Uses natural gas, propane, diesel vapor, or RNG already on site. Lowest cost pathway with proven technology.

  • Natural gas / propane / diesel vapor
  • Renewable natural gas (RNG)
  • Lowest cost hydrogen
  • No new fuel infrastructure needed
Zero Emissions

PEM Electrolysis

Produces the highest purity hydrogen from water and electricity. Zero point-source emissions when powered by renewables.

  • Water + electricity input only
  • 99.99%+ purity hydrogen
  • Simple integration
  • Pairs with solar, wind, or battery storage
High Efficiency

Solid Oxide Electrolysis (SOEC)

Very high efficiency electrolysis using waste steam. Ideal where heat is already available on site.

  • Hospitals, food processing, refineries
  • District energy and power plants
  • Utilizes waste heat as input
  • Near-zero CO₂ with clean electricity
Circular

NOx-to-Ammonia Systems

Converts exhaust NOx into the ammonia reagent itself — a fully circular NOx reduction architecture.

  • NOx from exhaust as feedstock
  • Produces NH₃ on demand
  • Eliminates DEF logistics entirely
  • Strong fit for H2SCR™ architecture

Reference Data

Hydrogen production methods compared.

Major commercial and emerging pathways by feedstock, purity, CO₂ impact, and commercial readiness.

Method Feedstock H₂ Purity CO₂ Emissions Status
Steam Methane Reforming (SMR)Natural Gas99.9%+HighCommercial
SMR + Carbon Capture (Blue H₂)Natural Gas99.9%+MediumCommercial
Alkaline ElectrolysisWater99.5–99.99%Grid-dependentCommercial
PEM ElectrolysisWater99.99%+Near zero*Commercial
Solid Oxide Electrolysis (SOEC)Steam99.9%+Near zero*Emerging
Biomass GasificationBiomass95–99.9%Low to negativeEmerging
Biogas ReformingBiogas / RNG99.9%+LowCommercial
Methane PyrolysisNatural Gas99.9%+Very lowEmerging
Ammonia CrackingNH₃99.9–99.999%LowGrowing
Coal GasificationCoal99.9%+Very highDeclining

* When powered by renewable electricity.

Ready to integrate H2SCR™ into your product line?

CMXI.org is the commercialization partner for H2SCR™ and is currently accepting OEM licensing inquiries. Generator, engine, and emissions control manufacturers are invited to discuss integration.

Email Daniel Wells — daniel@cmxi.org
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