WP1 – Specifications

Led by EPFL

Key parameters on the novel concepts of heterojunctions, design of efficient photoelectrodes, development of photocatalytic systems, design of PEC tandem systems and testing protocols are specified with the contribution of all partners at the beginning of the project.
D1.1: Report on specifications for WP2 developments

Specifications on simple and complex photocatalytic composites. The key parameters to target efficient and promising photocatalytic systems are the resulted optical, electronical, surface, structural, morphological properties, and most important the intimate contact between the different material components on each heterostructure composite proposed.

D1.2: Report on specifications for WP3 developments

Specifications for the photoelectrodes. Definition of adequate substrates to maximize conductivity and transparency for the ulterior development of tandem architectures. Accelerated Testing Protocols are defined to assess the stability of the photoelectrodes.

D1.3: Report on specifications for WP4 developments

In the photo-electrochemical approach the faradaic efficiency of ethylene is the most critical parameter for assessing the performance of the new as-prepared catalysts. In the photocatalytic approach the massic CO2 reduction conversion to ethylene, including the quantum yield are the key parameters for assessing the performance of the new as-prepared catalysts.

D1.4: Report on specifications for WP5 developments

Specifications that are required for the efficient integration of components into the final PEC device and to ensure its stability. Specification of the key parameters for optimising and evaluating the tandem PEC device.

WP2 – Advanced concepts for efficient light harvesting and charge carriers separation

Led by CNRS

The main objective of this WP is to develop light harvesting photocatalytic systems for exploitation in direct photocatalytic CO2 to ethylene reactors. The resulted nanomaterials will be in-depth characterized towards the understanding of structure-(photo) activity relationships, and the most promising will be transferred to WP6 for their implementation into flow photoreactors under simulated conditions.
D2.1: Report on active and robust binary SC1-SC2/SC-(MOFs) composites
D2.2: Report on active and robust bi-metallic M1-M2/SC1-SC2or M1-M2/SC-(MOFs) composites
D2.3: Report on the understanding of the physicochemical properties of the as-prepared materials

For more information, you can download & read the full deliverable 2.3 here.

D2.4: Report on the identification of the optimal synthetic methods, combination and proportions of materials

For more information, you can download & read the full deliverable 2.4 here.

D2.5: Report on the prediction of the behaviour of the materials from T2.1-2 for theoretical/rational design of composites

Application of Axiomatic Design Theory to Type II and Z-scheme type photosynthetic complexes. The upper limits for ethylene production rates for different combinations of semiconductors are identified and quantitative estimates are presented for both concepts. Strategies to enhance the overall production rate are proposed.

For more information, you can download & read the full deliverable 2.5 here.

WP3 – Optimization of light harvesting and charge carrier separation on photoanode and photocathode

Led by INAM

The main objective of this WP is the development of upscalable efficient metal oxide heterostructured photoanodes and photocathodes for the integrated device targeted in WP4-WP5 and tested in simulated conditions in WP6. Furthermore, detailed understanding of physical-chemical operation mechanisms related to light harvesting and charge separation by different electrical, optical and infrared spectroscopic tools, underpinned by modeling will be essential for the optimized design of photoelectrodes.
D3.1: Report on structural, optical and electronic properties of heterostructured BiVO4 photoanodes and Cu2O photocathodes
Monoclinic BiVO4 photoanode has a band gap energy of 2.4 eV (516 nm wavelength), which gives a theoretical solar-to-hydrogen (STH) efficiency of ~9.2%. The hole diffusion length of BiVO4 is 70 nm. BiVO4 can be combined with other materials to form heterostructures like WO3 which has adequate band positions to minimise electron/hole recombination in BiVO4. Cu2O photocathode has band gap energy of 2 eV (600 nm wavelength of light) which gives a theoretical STH efficiency of 18%. The diffusion was calculated to be 200 nm. A Cu2O based photocathode is generally composed of several different layers. To improve the charge carrier separation, an Au layer is placed at the bottom for hole transport and an Al:ZnO (AZO) layer is at the top for conducting electrons. A protection layer, usually TiO2, is deposited on top of the AZO layer. This helps to improve the stability significantly.
D3.2: Report on the fundamental processes leading to photoanode and photocathode operation
To study fundamental processes, labscale BiVO4 electrodes were synthesised. These methods were optimised. For comparison, TiO2 and Fe2O3 samples were also studied. Samples were studied using a range of techniques including temperature dependent photoinduced absorption, transient absorption and electrochemical impedance spectroscopies. These have yielded new understanding of how the rate of reaction depends on applied bias. An additional highlight is the development of spectroelectrochemial methods for understanding the optimal co-catalyst to use with photoanodes, in order to reduce the voltage required for reaction. To demonstrate the versatility of this technique to the SUN2CHEM project, several catalysts were synthesised and compared, including CoFe-Prussian blue and CoOOH. The results show that CoFe-PB is a suitable co-catalyst due to its ability to obtain reasonable turn over frequencies (TOF) at low coverages (θ) of catalytic states.
D3.3: Efficient BiVO4 photoanode with a photovoltage of 1 V delivering a photocurrent of 7 mA·cm-2 at 1.23 V vs RHE in an inner sphere redox couple with area of 1 cm2

We have been optimising the synthesis of BiVO4 photoanodes to achieve the targeted photocurrent (7 mA·cm-2 at 1.23 V vs RHE in an inner sphere redox couple). To do this, we have explored different deposition conditions and heterostructuring strategies using different electron selective layers (TiO2 and WO3) and co-catalysts (CoFe-PB). The best performance achieved at M18 is 4.5 mA·cm-2 for a 1 cm2 photoelectrode with an exposed area of 0.2 cm2. To achieve a higher performance, different approaches are under investigation, like the deposition of ultrathin metallic underlayers on top of the FTO substrates.

D3.4: Efficient Cu2O photocathode with 1.2 V photovoltage and 12 mA cm-2 photocurrent at 0V vs. RHE with area of 1 cm2
We realised Cu2O/Si 2T tandem photocathode that could achieve photocurrent density of 10 mA/cm2 @ 0.0 VRHE and photovoltage more than 1600 mV, in collaboration with University of Twente (Prof. Hans Gardeniers) and EPFL (Prof. Christophe ballif). Nano structured feature of Si bottom cell provided shorter charge transfer and higher light scattering, while additional voltage was achieved by Si cell itself as well. The photocathode presents the highest performance ever reported for Cu2O based photocathode.

WP4 – Development of solar-driven catalytic systems

Led by EPFL

The activities of WP4 comprise: the develop of efficient catalytic systems with advanced electrocatalysts for overall CO2 reduction to ethylene with the PC systems in WP2 and PEC systems in WP3. The introduction of protective layers on the photocathode and photoanode developed in WP3 to improve their stabilities under catalytic conditions. The development of novel electrocatalysts for catalytic CO2 reduction to ethylene in WP2-WP3 systems. The design of electrocatalysts for anodic water oxidation or organic oxidation for the photoanode.
D4.1: Report on efficient electrocatalyst for the selective reduction of CO2 to ethylene with faradaic efficiency of more than 70%

We have developed Cu based electrocatalysts, including monometallic Cu derived from different precursors, Cu based bimetallics, Cu based trimetallics as well as molecular compound modified Cu films to achieve efficient electrosynthesis of ethylene from CO2 reduction reaction. The performance of all the catalysts was investigated in an alkaline flow-cell configuration. As a result, we have achieved a best Faradaic efficiency of 72% towards ethylene production on the Cu catalysts by optimizing the local microenvironment.

D4.2: Report on photocathodic reduction of CO2 with the partial current density of 5 mA cm-2 for ethylene production
We realised PSC based photocathode using oxide drived OD Cu/Cu catalyst to achieve C2H4. Despite total photocurrent density at -0.4 VRHE, which is reasonably lower than electrochemical C2H4 (-1.0 VRHE), partial current density reached ~-1.3 mA/cm2 total for C2H4. Further investigation and development are in progress to further improve this type of device.
D4.3: Report on the synthesis of earth abundant water oxidation electrocatalysts and the protocol for deposition on photoanode
Earth abundant water oxidation electrocatalysts were prepared with electrochemical deposition of Ni followed by electrochemical modification of Ni to make it electrocatalytically active. The procedure was optimised with SPE electrodes and the optimised electrocatalyst was deposited on FTO/BiVO4 photoanodes provided by INAM. The as-prepared electrode has been tested for the electro- and photoelectrochemical oxidation of methanol, exhibiting good performances in the chosen conditions.
D4.4: Report on the optimization of process variables for PEC and catalyst development
Application of Axiomatic Design Theory to PEC cells and calculations about the ideal combinations of bandgaps of solar cells based on different OER and CO2RR catalysts. Additionally, strategies such as varying the density of catalyst on the photocathode and concentrating solar light are also investigated.

WP5 – Integration and stability assessment

Led by INSTM

All the most promising components investigated and developed in previous WPs (heterojunction nanomaterials, plasmonic composites, photocathode, photoanode, electrocatalysts) are integrated into a complete PEC device, the stability of the PEC device is assessed, and the deactivation pathways are identified.
D5.2: Report on tandem device combining photocathode and photoanode (area 2 cm2) for solar-driven CO2 reduction partial operating current density of less than 53 mA cm-2 and solar-to-ethylene efficiency of less than 4%
Report on the development of photoelectrochemical CO2 reduction reaction (CO2 RR) with tandem photoelectrode that is composed with BiVO4 photoanode jointed with 2 terminal Perovskite – Silicon Solar Cell (PSC/Si) modified with Cu electrocatalyst. Modest sized BiVO4 (1.5 cm2) – PSC/Si (1.5 cm2 ) – CuOx (0.1 cm2 ) device achieved unbiased photocurrent density of 3.3 mA cm2. BiVO4 – PSC/Si – CuOx device also achieved C2H4, however, partial current density around ~0.1 mA cm2 only (faradaic efficiency of 2%), faradaic efficiency of tandem photoelectrochemical cell was significantly lower than electrocatalyst only (~25%) or PSC/Si – CuOx integrated device (5%).
D5.3: Report on an integrated flow cell to reduce CO2 with optimal mixing properties

The development of a 3D printable continuous-flow cell has been studied. Different iterations have been developed, assembled, and tested for the continuous flow photoelectrooxidation reaction. An optimized design for the photoelectrocatalytic reduction of CO2 has been proposed.

WP6 – Test in a simulated environment

Led by ICIQ

The main objective of this WP is the validation of SUN2CHEM photo-assisted CO2 to ethylene processes (photocatalytic from WP2 and tandem cells from WP3-5) in relevant working conditions. The reactors and tandem prototypes will be benchmarked to identify the strength and weaknesses in terms of efficiency, production rates, stability, robustness, etc. The results will be analysed to define optimisation strategies and optimum architectures, along establishing future perspectives for further upscaling and industrial scope.
D6.1: Definition of electrochemical testing protocols for tandem cells

This report on the definition of electrochemical tests for WP5 describes the experiments and key parameters that will be used to determine the optimum working conditions, with inputs (electrolyte, flow rate, reagents concentration, stability to maximize performance towards the desired products, etc.) and efficiency losses of the tandem devices due to device design and construction. This knowledge will be useful to propose optimization strategies to improve and consolidate device performance under light irradiation.

D6.2: Definition of photoelectrochemical testing protocols for tandem cells under simulated sunlight

The report on the definition of photoelectrochemical tests under simulated sunlight for WP6 describes the experiments and key parameters that will be used to determine the optimum working conditions, with inputs (electrolyte, flow rate, reagents concentration, stability to maximize performance towards the desired products, etc.) and efficiency losses of the tandem devices when working under simulated sunlight due to device design and construction. This knowledge will be useful to propose optimization strategies to improve and consolidate device performance under light irradiation.

D6.3: Definition of photochemical testing protocols for PC systems under simulated sunlight
D6.4: Report on tandem cells performance under simulated sunlight irradiation and optimisation roadmap

WP7 – Environmental LCA, LCC, and Social Acceptance

Led by AU

The aim of this work package is to provide support for the sustainable development of energy-rich chemicals production (such as ethylene) from photoelectrochemical and photocatalytic conversion. The focus will be on methodology developments needed to perform both economic and environmental assessment of ethylene production, as well as the examination of the potential level, or lack of, social acceptance for converting sunlight to storable chemical energy.
D7.1: Report on needed data to build model for LCA and LCC

Specifications on the methodology that will be implemented for the realisation of the LCA and LCCA analysis of the different alternative pathways to produce ethylene, and definition of the common functional unit for both analyses. The document emphasises on the need for precise information on the innovative PC and PEC processes, that will have to be collected by the partners before making these environmental and economic analysis.

D7.2: LCA and LCC of ethylene production from different PEC configurations, and at different TRL
It is imperative to properly establish the potential environmental and economic benefits and drawbacks of producing ethylene by photocatalysis (PC) and photo-electrocatalysis (PEC) reduction of CO2. In this work, both technologies are assessed using lab scale data from partners (INAM, CNRS and EPFL). This report presents the Goals and scope definition, the Assessment methodology followed for the environmental and the economic assessment, the parameterized Inventory analysis and finally the detailed LCA results and Economic assessment results of the two technologies studied.

For more information, you can download & read the full deliverable 7.2 here.

D7.3: Report on social acceptance study and impacts on energy security
This report covers a comprehensive study that examines and determines the potential level, or lack of, social acceptance for converting sunlight to storable chemical energy, and identifies key stakeholders in the three layers of acceptance (policy, market, social) – to the best of our knowledge.

For more information, you can download & read the full deliverable 7.3 here

WP8 – Market analysis and roadmap to upscaling

Led by SOL

This WP sets in place processes and tools to ensure that the right foundations will be put in place during the course of the project for the concepts, scientific results, tools and methodologies to become successful commercial applications in the future beyond the scope of the project and when higher TRL levels are reached.
This implies extensive market intelligence activities in order to identify relevant market trends and competitive threats aligning project outputs with the external business environment, requirements and standards. The WP also offers a study on the upscaling of project results towards the TW scale in order to understand the potential of developed innovations and the feasibility of large-scale developments or whether it is more appropriate and relevant to particular market niches and uses. Moreover, the definition of the exploitation strategy will establish the internal structure of the consortium in terms of access and ownership rights to eliminate any source of IP conflicts in future commercial applications as well as viable business models/plans and valuations for taking project results to market.
D8.1: Market assessment
Identification of main regional trends and markets of interest for the developed Key Exploitable Results (application of market and competitiveness assessment tools such as Porter’s 5 Forces). The objective is to establish potential market applications for a minimum viable product of the SUN2CHEM technology once TRLs have been increased further and the technology is more cost competitive beyond the scope of the project.
D8.2: Roadmap for upscaling towards TW scale
D8.3: Exploitation plan

This deliverable provides the final outcomes of activities undertaken until the end of the SUN2CHEM project in task 8.3 dedicated to developing sound exploitation strategies behind the project Key Exploitable Results (KERs). The task aims to establish ownership rights of partners over the background and foreground surrounding KERs of the project and the possible provisions and agreements to be foreseen to reach consent around the commercial exploitation of research outputs. The consortium has conducted a series of activities towards the definition of a plan for the optimal exploitation of tangible and intangible KERs.

WP9 – Communication, dissemination, and networking activities

Led by EQY

This work package focuses on the communication and dissemination of the results, aiming for a strong exploitation after the life of the project. Tailored activities will be planned to specifically reach the right target public. IPR and data management are also treated within this WP to ensure a implementation of the project in accordance with the EU regulations. Last, synergies with other ongoing initiatives and projects are made, with a particular focus on Mission Innovation events.
D9.1: Data Management Plan
All of the SUN2CHEM partners are following Data Management Plan to deposit data (specific objects related to deliverables and scientific outcome) achieved during project progression. Specifically, experimental data will be generated within mechanistic understanding of light harvesting and charge separation, reactor design and optimisation, the operation of both photoanode, photocathode and photocatalysts. Characterization data of the final devices might also include SEM, TEM, XRD, IPCE, FTIR, Raman, TAS and synchrotron analyses. Such data will consist of numerical values for the measurements, stored in table form in common software e.g., Microsoft excel. Data Management Plan will consider basic principle for its conduction to encourage data accessibility, interoperable, reusable and consider ethical aspect for this process.
D9.2: IPR report
D9.3: Communication and dissemination plan
General strategy for communication and dissemination content and activities to address the 6 targeted audiences defined: R&D communities, industries, policy makers, investors, end-users and other H2020 projects. Definition of the key performance indicators (KPIs) to monitor the impact of the activities performed all along the project lifetime.
D9.4: Project website in English
Presentation of the first version (March 2021) of the website design and content which has been structured in a way that is informative, easy to navigate through and can target all different types of stakeholders and visitors.
D9.5: Report on networking activities and Mission Innovation challenge

WP10 – Project management

Led by EPFL

The objective of this WP is the overall coordination, the administrative, financial and contractual management of the SUN2CHEM project in order to ensure effective and efficient processes within the project and on the same time minimising (as much as possible) administrative overhead within all activities leading to the smooth realisation of SUN2CHEM´s goals. Activities of the management include the coordination of technical activities and progress monitoring according to the work-plan, timely reporting and providing of other required information to the European Commission, coordination of the delivery of all reports and deliverables, organization of risk management and introduction of preventive actions and the organization of meetings of the General Assembly.
D10.1: Tools for management and information flow
Presentation of the different tools that have been prepared in the first months of the project to facilitate its management by partners: deliverables and presentation templates to be used by partners, a pCloud shared repository, an Excel document to facilitate monitoring of staff effort and costs spent on the project by each partner.
D10.2: Quality plan
Result generated during conduction of the SUN2CHEM project will be evaluated by the Quality plan set by the consortium, specifically by the quality management to confirm status of project progression.
D10.3: Project performance report
All the SUN2CHEM partners are conjointly developing the components to be integrated into the tandem photoelectrochemical cells, targeting ethylene as the final product from the efficient solar-driven CO2 reduction. This deliverable presents the major progress that has been achieved during last 18 months in each Work Package (WP), mainly from WP1 to WP4. All the testing protocols have been specified with the contribution of all partners. The development and optimisation of heterojunctions, photoanode, photocathode as well as electrocatalysts for ethylene production have been reported in detail.