#	Pagina
attuale pagina	/open-h2020/projects/212842/results.html

Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - FotoH2 (Innovative Photoelectrochemical Cells for Solar Hydrogen Production)

Teaser

Summary

The increasing importance of renewable energy sources will facilitate carbon-free energy pathways, but it will demand efficient energy storage, for instance in chemical bonds. In this respect, hydrogen as an energy carrier is especially appealing as it can be the basis of flexible and open energy systems when combined with fuel cells. In this context, photoelectrochemical devices are particularly attractive as they facilitate the direct conversion of solar energy (combined or not with electricity) into chemical energy. The use of solar energy for photoelectrochemically splitting water has been widely investigated for producing sustainable hydrogen, although no commercialisation of this technology has emerged. Currently the main obstacles to commercialisation are low solar-to-hydrogen efficiency, expensive electrode materials, fast degradation of prototypes, and energy losses in separating the electrolysis products from water vapour in the output stream. The FotoH2 project follows a new scientific direction for achieving cost-effective solar-driven hydrogen production, and it has the capability of large-scale prototyping and field testing the proposed technology. FotoH2 introduces anion-exchange polymer membrane and porous hydrophobic backing concepts in a tandem photoelectrochemical cell based on abundant, non-critical materials. This approach allows the use of cost-effective metal oxide electrodes with optimal bandgaps and a simple flow-cell design without corrosive electrolytes. The main elements in the FotoH2 materials and design choices can be business drivers. The goal is to upscale the device by validating the technology in a system with a module of 1 square metre and achieve a photoelectrolysis device with high solar to-hydrogen efficiency and long lifetime. The project aims for breakthroughs in cell lifetime, conversion efficiency, cost-efficiency, and hydrogen purity. To bring these innovations to market, an exploitation plan is also addressed.

Work performed

The main objectives of this work period were: (i) To establish the management, communication and reporting systems necessary to support the effective delivery of the FotoH2 project; (ii) To start work on the core RTD Work packages (WP2, WP3, WP4 and WP5) covering the specifications, the electronic and continuum modelling and the individual developments of the electrode materials, polymer electrolyte membrane, co-catalysts and the prototyping of the unit cell and part of the ancillary equipment for the panel; (iii) To set up a public web-site to support the dissemination and promotion of the FotoH2 project.
In the first 18-month period of the FotoH2 project, an effective start-up and initial phases of the project have been completed. The consortium members are working together effectively, with strong collaborative relationships being established between partners. All partners are contributing to the project delivery and the Work Package leaders are managing the individual Task activities efficiently.
The main technical achievements in the FotoH2 project so far:
(1) Functional and operational requirements for the planned solar hydrogen production system have been specified. These requirements once validated for mutual compatibility and completeness have been mapped onto component-specific technology requirements.
(2) The test site setup and integration planning has been performed.
(3) Electronic modelling has allowed the consortium to screen a series of ternary (and some quaternary) oxide materials as potential candidates for photoelectrodes, using as criteria the calculated band gap and location of the band edges, type of optical transition and effective carrier masses. Results have revealed two significant limitations of these materials: a relatively wide band gap and relatively large carrier effective masses.
(4) Device-level modelling has been addressed following both an analytical approach and computer simulations. Importantly, this modelling activity has validated the potential of a tandem based on hematite and cupric oxide to reach a solar-to-hydrogen efficiency of 11 %.
(5) The characteristics of the main components of the system have been specified, including sizes and preparative/synthetic methods.
(6) Benchmarking of the materials selected from the screening tasks has been addressed. However, none of the studied materials outperformed the couple of materials initially chosen.
(7) Electrode materials (hematite and cupric oxide) as well as appropriate co-catalysts are being optimized paying attention to both nanostructuring and doping on the one hand, and to the nature of the interface between semiconductor and co-catalyst. The optimization has progressed better in the case of the photoanode.
(8) Significant progress has also been achieved in the development of adequate polymer electrolyte membranes and hydrophobic carbonaceous backings as well as in the tailoring of the interfaces of these components with the photoelectrodes. Very importantly, in the course of the first reporting period, the general concept of the project has been validated and a step change in efficiency has been achieved although further improvements are needed to meet the project objectives.
(9) Prototyping of the photoelectrochemical unit cell has been performed with attention to water and hydrogen management.
(10) A detailed life-cycle analysis has also been addressed in this period and will be completed in the second reposting period.

Final results

The FotoH2 project is going beyond the state of the art in the field of photoelectrochemical hydrogen production as it follows a novel, cost-effective, quasi-solid-state approach to a water splitting tandem photoelectrolyser. The expected results remain as anticipated at the start of the project. By project completion, a system including a photoelectrochemical panel, exposing an active area of 1 square meter and showing efficient solar-to-hydrogen conversion and long lifetime will have been build and robustly trialled, including both laboratory and field testing. The expected impacts of the project include diminishing both geographical constraints for low carbon energy production and the barriers to increase the penetration rate of distributed and intermittent renewable energy sources. The development of a successful photoelectrolysis technology will contribute to the reduction of environmental pollution and mitigation of climate changes. The carbon-free production of hydrogen should favourably impact on the European leadership in sustainable hydrogen technologies and contribute to the broad implementation of fuel cells, including automotive applications. More broadly, the successful development of the technology would enhance innovation capacity and new market opportunities to strengthen competitiveness and growth of companies operating in the field of solar energy conversion and hydrogen. Further quantification of these benefits is a key subject of the project is being comprehensive addressed in an ongoing work package that focuses among others on lifecycle analysis and economic impacts. Finally, the FotoH2 project aims at exploring new knowledge and exploitation pathways to ensure the partners can take advantage of them and thus contribute to the further development of a knowledge-based economy in Europe.