Expected Impacts

The SUN2CHEM project focuses on the simultaneous development of a photocatalytic reactor and a tandem photoelectrochemical device performing the solar-driven reduction of CO2 to energy rich chemicals such as ethylene. To achieve this goal, the consortium will work on all components of the devices: novel heterojunctions, photoelectrodes, catalysts, protection layers, membranes and photoelectrochemical and photocatalytic mechanisms. Ethylene, with 862 Mt CO2e per year of potential emission reduction, is by far the most impactful energy rich chemical to tackle when willing to mitigate climate change. Producing this chemical from sunlight and abundant resources (CO2 and H2O) is promising in reducing carbon emissions. The efficient production of CO2-free ethylene represents a major breakthrough in sustainable development. The main objective of SUN2CHEM is to achieve 3% solar-to-ethylene PEC efficiency with 50 cm2 photoelectrodes and 5% solar-to-ethylene photocatalytic efficiency.

Impact’s KPIs:

• 1 cm² PEC solar to fuel efficiency: 4%
• Upscaled 50 cm² PEC solar-to-fuel efficiency: 3%
• Loss of activity < 10% over 1000h of operation
• Ethylene production rate: 9 µmol.cm^-2.hr^-1
• 30% decrease of land-use compared to fossil-based ethylene

The SUN2CHEM technologies will allow the production of storable chemicals. As the targeted molecules can be stored for a virtually unlimited time, they offer enhanced availability and flexibility of use, thereby securing provision of chemical feedstock for the end-users. The development of such technologies to replace fossil resources or generate chemicals instead of replace exploiting fossil resources can also ensure a more reliable energy supply to developing countries by directly integrating on-land solar-driven production. The transportation of energy rich chemicals being easily performed, it answers one of the most critical energy security issues for such countries. Therefore, economic development through facilitated energy supply can be ensured.

The development of novel, environmentally friendly technologies to produce a very valuable chemical, used worldwide, would contribute to establish a European-based innovation asset. The direct photocatalytic conversion of CO2 to ethylene and tandem PEC conversion of CO2 to ethylene have never been addressed before due to the complexity of the 12-electron transfer process. Here SUN2CHEM integrated the expertise from different disciplines including materials scientist, spectroscopic chemists, electrochemists, catalysis scientists and engineer to tackle this scientifically challenging process. The success will lead Europe as the global leader in developing novel CO2 to ethylene systems. SUN2CHEM technologies, have a potential industrial impact, being able to compete in costs but also in societal acceptance, since it is based on renewable energy and materials that are mostly affordable/abundant.

Impact’s KPIs:

• Unprecedented large-area PEC prototype device for CO₂ reduction to ethylene (50 cm²)
• Record breaking efficiency for solar-to-ethylene in PEC system
• Novel concept of using PC system to generate ethylene from CO₂
• Targeted year of maturity of the developed technologies at industrial scale: 2050

Through the development of new renewable energy technologies with medium-term upscaling potential, SUN2CHEM brings a significant contribution to a sustainable renewable energy system. Even if ethylene is not typically considered a fuel, the development of our sunlight to ethylene technology would have a dramatic effect on the industrial energy consumption: SUN2CHEM ethylene could substitute the current ethylene commercial production, obtained mainly from the cracking of multiple hydrocarbons (fossil fuels). It can also be used as a fuel if the market conditions are favourable and ethylene is sufficiently cheap. The use of these fossil fuels as raw materials must be avoided as to meet the future clean energy European targets. The use of solar energy to produce valuable chemicals instead of plain fuels may be an easier way to reach renewable energy penetration into industrial scale production processes at an affordable cost.

Impact’s KPIs:

• >70% reduction in CO₂ emissions compared to standard methods to produce ethylene at horizon 2050
• 100% reusable and recyclable materials used

SUN2CHEM partners are strongly committed towards enhancing international collaboration on the topic of solar fuels and several of them are national representants of Mission Innovation’s “Converting Sunlight Innovation Challenge”:

• Prof. Michael Grätzel from EPFL is leading the Laboratory of Photonics and Interfaces, with particular interest in harvesting solar energy with photovoltaics and photoelectrochemistry. His research on generation of solar fuels is intensively collaborated not only with partners within Europe, but also scientists from Asia and Middle East.
• Dr. Valérie Keller-Spitzer from CNRS is the leader of the French Solar Fuels (GDR) research consortium aiming at enhancing national networking, collaboration, and cohesion of the research groups dedicated to solar-driven fuel production. IFPEN is also part of this initiative.
• Prof. Leif Hammarström from UU is the chairman of the Swedish Consortium for Artificial Photosynthesis, which is part of the Solar Fuels Institute (SOFI) gathering leading researchers from all over the world and enhancing international networking and collaboration. The consortium is a member of the European Energy Research Alliance (EERA). Prof. Hammarström is also the Swedish expert for Mission Innovation’s IC5 challenge mentioned in the call.
• Prof. Huub de Groot from ULEI coordinates the H2020 SUNRISE initiative, in which ICIQ, ICL and UU are also involved, aiming to build a strong interdisciplinary community committed towards building a clean energy future through the development of artificial photosynthesis.
• Prof. James Durrant from ICL is the founding director of UK’s Solar Fuels Network developing an effective community of solar fuels researchers and promoting collaboration between both academia and industry. He is also national expert for Mission Innovation’s IC5, which is tackled by SUN2CHEM.
• Prof. José Ramon Galan-Mascaros from ICIQ is the coordinator of the H2020 A-LEAF collaborative project, in which INAM, ICL and ULEI are also participating, in the international development of a PEC device to produce C1 products (carbon monoxide and formate) from sunlight, water and CO2.
• Prof. Jason Yeo from NUS is the leading Principal Investigator in SinBeRISE initiative and CARES. Both consortiums aim at establishing collaborations between Singapore and universities worldwide including Cambridge and Berkeley for developing innovative renewable-energy solutions.
• Prof. Masakazu Sugiyama from UTO founded international joint laboratory LIA-Next PV with French collaborators including INSIS, INC, the University of Bordeaux and RCAST. The consortium aims at establishing close collaborations between Japan and French for developing photovoltaic cells.

These positions will be used as precious resources along the life of the project to encourage and deepen international collaboration. Several events will be organised in the project notably in the framework of Mission Innovation such as workshops seminars.
In addition, the project itself gathers renowned researchers from 11 different countries to work in close collaboration, thus strengthening interconnections between organisations and opening opportunities for further collaborative projects.

SUN2CHEM aims at developing up-scalable systems for solar-driven CO2 reduction to energy-rich chemicals such as ethylene. With the TRL 5 target achieved, the results generated from SUN2CHEM may attract the attention from mature industrial giants in Europe who are interested in CO2 capture and conversion technology.
While more and more start-up companies appeared in the United States aimed at carbon dioxide conversion such as Dioxide Materials and Carbon Engineering, there is only a few start-ups in Europe that tackles the CO2 capture and conversion. The scalable systems for ethylene production from sunlight developed in SUN2CHEM may induce more investors interested in developing technology for converting CO2 to valuable chemicals.

SUN2CHEM aims at not only producing chemicals from the sun, but also converting excessive CO2 to useful products. The reactant, CO2, is not only an unwanted molecule, but also the main driver of climate change issues. SUN2CHEM will address the latter issues by developing technology for turning carbon dioxide into more valuable chemicals.

Ethylene production is performed at large-scale using fossil energy. Producing solar ethylene represents a ground-breaking way of decarbonising the corresponding industrial processes, thus increasing sustainability. The comparison between the different ways of producing ethylene will be done as part of the LCA during the project.