Catalyst development for low-cost large-scale sustainable hydrogen production from seawater and renewable energy

Hydrogen is considered one of the most promising clean energy carriers, thanks to its high gravimetric energy density (142 MJ/kg) and environmentally friendly use. It is a clean and desirable way to produce pure hydrogen at the cathode via electrolysis of water driven by renewable energy, however, the water splitting is highly dependent on having an efficient and stable oxygen evolution reaction (OER) at the anode, to counterbalance the hydrogen evolution reaction (HER) at the cathode. Furthermore, if water splitting is used to store a substantial portion of the world's energy, water distribution issues may arise if vast amounts of purified water are used for hydrogen fuel production. On the other hand, seawater is the most abundant aqueous electrolyte feedstock on Earth but its implementation in the water-splitting process presents many challenges, especially for the anodic reaction.

The most serious challenges in seawater splitting are posed by the chloride anions (around 0.5 M in seawater). Under acidic conditions, the OER equilibrium potential is only slightly higher than that of chlorine evolution, e.g., by 0.130 V, and in fact the OER is a four-electron oxidation requiring a high over potential while chlorine evolution is a facile two-electron oxidation with a kinetic advantage. While chlorine is a high value product, the amount of chlorine that would be generated to supply the world with hydrogen would quickly exceed demand.

Nevertheless, under alkaline conditions, the equilibrium potential of OER is significantly shifted to lower value but that of chorine evolution does not change so much, which facilitates OER over chorine evolution with 0.490 V difference in potential domain. Therefore, this project aims to develop highly efficient OER catalysts with over potential less than 0.480 V under alkaline conditions, as well as highly efficient and low cost HER catalysts such as transitional metal carbides and nitrogen doped carbon nanomaterials.

The RI self-assessment of an individual's research projects will mean that the cohort have a high degree of understanding of the potential beneficial impact from their research on the economy, society and the environment. This then places the cohort as the best ambassadors for the CDT, hence most pathways to impact are through the students, facilitated by the CDT.

Industrial impact of this CDT is in working closely together with key industry players across the hydrogen sector, including through co-supervision, mentoring of doctoral students and industry involvement in CDT events. Our industrial stakeholders include those working on hydrogen production (ITM Power, Hydrogen Green Power, Pure Energy) and distribution (Northern Gas, Cadent), storage (Luxfer, Haydale, Far UK), safety (HSL, Shell, ITM Power), low carbon transport (Ulemco, Arcola Energy), heat and power (Bosch, Northern Gas).

Policy impact of the CDT research and other activities will occur through cohort interactions with local authorities (Nottingham City Council) and LEPs (LLEP, D2N2) through the CDT workshops and conference. A CDT in Parliament day will be facilitated by UKHFCA (who have experience in lobbying the government on behalf of their members) and enable the cohort to visit the Parliamentary Office for Science and Technology (POST), BEIS and to meet with local MPs. Through understanding the importance of evidence gathering by Government Departments and the role this has in informing policy, the cohort will be encouraged to take the initiative in submitting evidence to any relevant requests for evidence from POST.

Public impact will be achieved through developing knowledge-supported interest of public in renewable energy in particular the role of hydrogen systems and infrastructure. Special attention will be paid to demonstration of safety solutions to prove that hydrogen is not more or less dangerous compared to other fuels when it is dealt with professionally and systems are engineered properly. The public, who are ultimate beneficiaries of hydrogen technologies, will be engaged through different communication channels and the CDT activities to be aware of our work. We will communicate important conclusions of the CDT research at regional, national, and international events as appropriate.

Socio-economic impact. There are significant socio-economic opportunities, including employment, for hydrogen technologies as the UK moves to low carbon transport, heat and power supply. For the UK to have the opportunity to take an international lead in hydrogen sector we need future innovation leaders. The CDT supported by partners we will create conditions for and exploit the opportunities to maximise socio-economic impact.

Students will be expected in years 3 and 4 to undertake a research visit to an industry partner and/or to undertake a knowledge transfer secondment. It is expected these visits (supported by the CDT) will be a significant benefit to the student's research project through access to industry expertise, exploring the potential impact of their research and will also be a valuable networking experience.