Reduction of anthropogenic CO2 emissions is currently a global priority to mitigate the effects of climate change. Transport is one of the key contributors, with the road transport sector currently making up 21% of European CO2 emissions (1). Developing carbon neutral technologies to replace fossil-fuel based powertrains is now critical to achieve the climate goals set out in Paris Agreement signed in 2016. A diverse range of options have been proposed, including the introduction of electrified vehicles, with power stored either in a battery or hydrogen. A recent study has shown that more than 56,000 hydrogen-powered fuel cell vehicles have already been sold, with 30,000 of those in the last two years,(2) suggesting that fuel cell technologies are starting to gain traction. However, there are still some issues with public acceptance remaining, especially regarding hydrogen infrastructure and public perception about the cost, environmental impacts and overall efficiency (3). Toyota Motor Europe is the coordinator of the Horizon 2020 project, Sun-To-X (funded under grant agreement 264883), which aims to develop a system for green, liquid fuel production with applicability for hydrogen-powered fuel cell vehicles. In this project, solar-driven processes produce green hydrogen and this green hydrogen is stored through a thermochemical process in silicon hydride bonds. Our target fuel is HydroSil (4), which is carbon-free, energy dense and liquid under standard storage conditions. This would allow the use of the existing infrastructure for fuel transportation and storage for distribution. The HydroSil fuel can be simply reacted with water in the presence of a catalyst to release hydrogen. This can be done at a refuelling station or directly at the entrance of the fuel cell, where HydroSil is especially relevant in heavy-duty onboard applications. In this presentation, the latest technical updates on our green hydrogen production process and silicon hydride fuel will be presented. Technoeconomic analysis, lifecycle assessment and analysis on social perception of Sun-To-X technology will be explained along with the future perspectives. 1. Road transport: Reducing CO₂ emissions from vehicles (europa.eu) 2. Information Trends (09/02/23) 3. A. Vallejos-Romero et al. Sustainability 2023, 15(1), 303, https://doi.org/10.3390/su15010303 4. Hydrogen Stored as Liquids | HySiLabs

Mrs. Hannah Johnson, Senior Engineer, Toyota Motor Company