GreenH2 production from water and bioalcohols by full solar spectrum in a flow reactor

Project Information

GH2

Grant agreement ID: 101070721

DOI

10.3030/101070721

Project closed

EC signature date 9 June 2022

Start date 1 October 2022

End date 31 March 2026

Funded under

• The European Innovation Council (EIC)

Total cost

€ 2 201 654,72

EU contribution

€ 2 201 654,72

Coordinated by

ACONDICIONAMIENTO TARRASENSE ASSOCIACION
Spain

Periodic Reporting for period 2 - GH2 (GreenH2 production from water and bioalcohols by full solar spectrum in a flow reactor)

Reporting period: 2023-10-01 to 2026-03-31

Summary of the context and overall objectives of the project

Efforts are being made to reduce dependence on grey hydrogen from fossil fuels and blue hydrogen, combining fossil production with carbon capture and storage. Solar-driven water splitting offers a sustainable route to green hydrogen, using water and sunlight as renewable inputs. However, implementation remains limited by slow water oxidation, limited solar-spectrum use, and the cost and complexity of separating hydrogen from oxygen.

GH2 addressed these challenges by developing an alternative solar-driven route for co-producing hydrogen and value-added chemicals from bioethanol and water. Instead of producing oxygen through water oxidation, the process couples hydrogen evolution with bio-ethanol conversion into valuable carbon-containing products. This improves resource efficiency and supports hydrogen production through co-product valorisation, while avoiding direct CO2 formation.

To achieve this objective, GH2 investigated catalysts using UV-visible and infrared radiation, increasing the solar-spectrum share available for the process. Attention was given to catalysts and co-catalysts based on abundant and non-noble metals. The project also addressed flow reactor scale-up, membrane-based hydrogen purification, and environmental, economic, and societal assessment.

GH2 aligns with the Energy Union, the Strategic Energy Technology Plan, EU climate policy, and the European Green Deal. Its results support renewable hydrogen production, efficient use of bio-based resources, reduced dependence on fossil fuels and imported energy, lower reliance on noble and critical materials, and scalable, cost-competitive clean technologies.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

By the end of the project, substantial progress had been made in solar-driven catalysts for co-producing hydrogen and valuable chemicals from bio-alcohols. The work covered UV-visible, infrared, and thermally driven catalytic systems, reactors, membrane separation, modelling, and sustainability.
For UV-visible irradiation, active carbon nitride photocatalysts were developed for hydrogen production coupled with ethanol conversion. Optimised catalyst preparation improved activity and stability, while a lower-cost, non-noble-metal MoS2-based system demonstrated stable hydrogen production over 180 hours. Both systems were evaluated under real outdoor solar irradiation.
A new infrared-responsive Cu/Fe2O₃ catalyst was developed using abundant and non-noble metals. The catalyst converted infrared energy into heat to promote hydrogen and acetaldehyde production and showed promising performance under real sunlight. Copper-based thermal catalysts were also developed below 300 °C, achieving approximately complete ethanol conversion and acetaldehyde selectivity of up to 80%.
Advanced spectroscopy, microscopy, and computational modelling clarified light absorption, charge transfer, and surface reaction mechanisms. These results supported optimisation of catalyst composition, co-catalyst selection, and performance. Catalyst-coating approaches were evaluated on substrates, identifying suitable strategies for material classes.
Pt/CGCN and MoS2/CGCN were evaluated and optimised in the laboratory-scale flat-plate reactor. Wet deposition onto glass-fibre filters was identified as the most suitable immobilisation and support strategy. The reactor was scaled up by more than a factor of 20 using eco-design principles while maintaining performance with the non-noble metal catalyst.
Membranes were evaluated to separate hydrogen from acetaldehyde, with a polyimide-based membrane showing the greatest potential. Process modelling assessed integration of the reactor and membrane separation unit.
Lifecycle and techno-economic assessments indicated that the GH2 process could reduce the carbon footprint by approximately 50% compared with benchmark systems. The results identified catalyst lifetime, productivity, reactor scale, and co-product valorisation as key factors for competitiveness.
An agent-based model was developed and validated using data from hydrogen valley initiatives in Mallorca and the Northern Netherlands. The model supports green hydrogen value-chain planning, policy development, and investment prioritisation.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The optimised carbon nitride photocatalyst achieved an apparent quantum yield of approximately 73% for hydrogen production at 410 nm, among the highest reported for this material type. The system also operated efficiently in air and produced value-added compounds alongside hydrogen.
A lower-cost MoS2/carbon nitride catalyst maintained hydrogen production for 180 hours without using noble-metal co-catalysts, demonstrating a promising balance between activity, cost, and operational stability.
GH2 developed a high-performance Cu/Fe2O₃ catalyst for infrared-driven hydrogen production using abundant and non-critical materials. Its activity exceeded previously reported infrared-driven systems by at least one order of magnitude and remained competitive with leading UV-visible photocatalysts. Outdoor testing confirmed its potential to use a broader solar-spectrum portion.
The flat-plate reactor was scaled up by more than 20 times without performance loss with the MoS2-based catalyst. Together with membrane screening and modelling, this provided a technical basis for future integrated hydrogen and co-product production.
At system level, GH2 identified a potential carbon-footprint reduction of approximately 50% and a pathway towards competitive production costs through improved catalyst performance, larger reactor scale, and co-product valorisation. The validated agent-based model further showed the importance of industrial integration and co-product use for deploying green hydrogen value chains.