Photocatalytic covalent organic frameworks for hydrogen production and storage

COFs are among the most promising hydrogen storage materials, they are lightweight, robust and easily synthesised with high hydrogen storage capacity (>7 wt.%) and are much more stable than metal organic frameworks (MOFs) for long term use. However, like MOFs, these materials are network polymers, often with uniform pore sizes. While this allows gas molecules to enter easily there is little to stop them leaving just as readily, indeed at ambient temperatures the hydrogen storage capacity of both COFs and MOFs is typically around a third of that when measured at cryogenic temperatures.

In recent years, photocatalytic polymers and frameworks have also emerged as exciting new candidate in hydrogen evolution from water, the essentially infinite versatility and modular nature of organic molecules allows us to fine tune optical and electronic properties and thereby catalytic performance.

This project will produce photocatalytic molecular tectons based on dibenzothiophene-S,S-dioxide - one of the most promising organic fragments in hydrogen production from water - which will anchor over the pores in the surface of the COF through non-covalent interactions to create sites for hydrogen evolution from water and to reduce the size of the pores making them readily permeable to hydrogen but not oxygen to ensure that the COF becomes enriched in hydrogen exclusively, targeting a gravimetric capacity of 5 wt.% at 298K in the first instance. The US DOE has set a target gravimetric capacity of 4.5 wt % by 2020 and 5.5 wt % by 2025 for onboard hydrogen storage for light vehicles and the approach proposed here presents a genuine route to attaining this goal.

This approach will increase the thermal stability of the hydrogen enriched COFs at ambient temperatures and ultimately permit controlled generation, storage and release of hydrogen.

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.