The deployment of new and existing materials will play a critical role in delivering the growth of the hydrogen sector, identified as a cornerstone of the UK Government’s net zero ambitions. In this blog, Professor Phil Withers and Dr Robert Sorrell, from the Henry Royce Institute, lay out the research priorities on the path to wide scale hydrogen usage, and how policymakers can support and implement new developments in materials science.

• A new roadmap from the Henry Royce Institute identifies the challenges and opportunities in the UK taking a global lead in hydrogen technology
• One priority area for research is the introduction of hydrogen gas into domestic heating and national infrastructure
• Understanding how materials interact with hydrogen, including degradation over time, is fundamental to the transition to a low-carbon economy

With advanced plans for gigawatt scale low carbon hydrogen production, a programme investigating the conversion of natural gas networks to hydrogen, and various ongoing trials for fleets of hydrogen-fuelled cars, buses and vans, the UK is leading the way in terms of embracing the hydrogen economy.

This is precisely why here at the Henry Royce Institute for Advanced Materials we commissioned a study, published earlier this month, entitled ‘materials for end to end hydrogen’ that examines the critical materials research challenges the sector now faces. The report identifies a number of priorities key to supporting materials development and uptake, and how addressing these challenges will underpin the UK’s wider hydrogen energy sector leadership ambitions by providing potential materials solutions that can support its accelerated deployment.

Significant role

The significant role of hydrogen in driving the UK’s net zero agenda is widely acknowledged, with the government’s Hydrogen Strategy expected this year. The aim of our report, funded by the Engineering and Physical Sciences Research Council, was to highlight the key materials areas critical to enabling wide-scale hydrogen deployment in a 2050 timescale and to catalyse the investment and partnerships required to deliver technology breakthroughs in these areas.

In particular the report identifies six research priorities around hydrogen production, storage and distribution and use, and the need for a UK testing and accreditation facility.

It also sets out the materials research and development opportunities we need to progress now in order to enable the deployment of hydrogen as a viable energy source at scale by 2050. Further, it provides insights into early stage materials discovery and innovation which could accelerate our ambitions and deliver step changes in our ability to produce and deploy hydrogen.

Targeted support

The study demonstrates vividly that further targeted support is necessary to build a robust, efficient and sustainable hydrogen industry to support the UK’s net-zero aims. Action must be taken quickly to meet our 2050 commitments given the time it takes to deliver new materials systems. The key priorities identified in the study are:

*Reducing the need for critical materials in polymer electrolyte membrane (PEM) electrolysers to realise global electrolysis capacity ambitions at a terawatt scale.

Electrolysis is a promising way of using electricity to split water into hydrogen and oxygen. However, the leading electrolyser technology (PEM) contains rare and expensive elements to catalyse the process, increasing the capital cost of PEM electrolysers, and the cost of clean hydrogen.

The global production capacity of these rare elements will place limits on the electrolysis capacity that can be developed at current catalyst loading levels. Materials research targeted at reducing rare element loading will be required to realise PEM electrolysis capacity on a terawatt scale.

*Improving point of use hydrogen purification technologies, enabling large scale supply from the gas grid to hydrogen fuel cells.

In principle, hydrogen can be distributed effectively using the existing UK gas grid infrastructure, reducing the cost of hydrogen distribution, and enabling the powering of fuel cells to create clean electricity.

Given that hydrogen leaving the grid will be at relatively low purity, and fuel cells currently require high levels of hydrogen purity, improvements are required in downstream purification technologies close to point of use. This requires further development of the leading materials-based solutions, such as membranes and pressure swing adsorption. These technologies will need to be developed and deployed in collaboration with organisations including the Energy Networks Association, Gas Operators Network, National Grid, OFGEN, and energy suppliers as soon as possible to ensure the UK takes a leading role in the transition to a hydrogen-based gas network.

*Establishing a detailed understanding of materials degradation of the high volume compressors needed as part of the UK gas grid.

Transport of hydrogen in the gas grid is the responsibility of the gas network operators, and hydrogen levels will be increased in the first instance by blending with natural gas. This requires the use of compressors to take hydrogen to the pressures required for transmission and distribution.

The small size and light weight of hydrogen molecules, along with its ability to degrade materials, makes the design of long-lasting hydrogen compressors particularly challenging. Better understanding of compressor materials degradation in real world environments will enable challenges associated with materials selection and development to be understood and the effects of hydrogen degradation mitigated.

*Developing materials solutions for cost effective, conformable hydrogen tank storage in fuel cell vehicles.

Hydrogen-powered vehicles currently use gaseous hydrogen stored at 350 or 700 bar pressure in cylindrical vessels. Hydrogen storage tanks are the most expensive component in current hydrogen fuel cell cars and add significant weight. New materials solutions offering more conventional fuel tank shapes are therefore required to allow better use of on-board space and greater flexibility in vehicle design.

*Developing a UK capability to test, set standards, and accredit new materials.

Early-stage materials testing for some hydrogen applications has resulted widely varying methodologies. Developing standardised testing methodologies will increase confidence in results and collaboration between those undertaking research in the hydrogen space, and further cement the UK’s position as a leader in this field.

There is a role here for the Royce in terms of expertise, and for involving the National Physical Laboratory (NPL), the Health and Safety Executive (HSE) and the British Standards Institution (BSI) in supporting and legislating this.

*Improving catalysts for distributed ammonia production and cracking is needed, to realise ammonia’s potential as a hydrogen storage and distribution vector.

The relatively high density, efficiency of conversion, and moderate liquefaction temperature of ammonia has made it a key hydrogen carrier candidate. To support its use requires the development of efficient catalysts that allow ammonia to be produced on a distributed scale and enable it to be cracked more efficiently into hydrogen and nitrogen.

Next steps

One thing is clear; materials developments take time to research and implement and so the UK needs to act quickly and concertedly if we are to have the knowledge and materials data needed to safely adopt a hydrogen economy in time to meet our 2050 obligations. With this in mind, the Royce aims to facilitate identification of the resources and partnerships required to realise the UK’s leadership ambitions in these key materials fields.

To this end, a cross industry/academic group is developing a more detailed proposal outlining the research challenges, resources and capabilities required, and this proposal will be available by the end of July for consideration for inclusion in the November government spending review. There will be a role for BEIS in coordinating, sponsoring, and implementing the research priorities we have identified.

Through the success of our wind energy programme the UK has shown that it can lead the world in the development of green energy. We need to apply the same sense of urgency and clarity of focus in the forthcoming Hydrogen Strategy to ensure we are at the forefront of the hydrogen economy.

*You can read the full report on Materials for end to end hydrogen and summaries of the key materials research priorities here and you are welcome to feedback any comments to info@royce.ac.uk.

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