D2.1 - Report on site density and turn over frequency of selected benchmark catalysts

TOF and SD are two key descriptors in evaluating the single-site M-N-C catalysts for their ECO2R performance. In this WP, we improved the TOF and SD in our studied M-N-C candidates and deconvoluted their catalytic impacts.

D2.2 - Report on DFT prediction of selected benchmark catalysts

This deliverable reports on density functional theory (DFT) predictions of the activity and stability of single atom metal catalysts supported on nitrogen-doped graphene for CO2 reduction to CO. We find several candidates beyond Fe- and Ni- single site catalysts with promising activity. These efforts are part of the objective for SELECTCO2 to design electrolyzers with with 90% selectivity for CO2R to CO at high current densities. Promising candidates will be tested by the Strasser group at TU Berlin (WP2 leader).

D2.3 - Report on promising M-N-C catalyst activity showing progress toward WP targets

D2.4 - Final report on WP achievements in terms of activity of new catalysts

D3.1 Report on Co-catalyst approach towards ethanol production

Sluggish kinetics related to C-C coupling products limit the effectiveness of electrochemical CO₂ reduction to ethanol over Cu catalysts. The preparation of tandem catalysts by the deposition of two independent and adjacent layers on gas diffusion electrodes can enhance the reaction kinetics by increasing the local CO concentration. A series of Cu/Ag and Cu/Au electrodes were prepared, varying the composition through the deposition of a CO-selective layer on top of the Cu using both thin films and nanoparticles. This approach allows the Ag or Au to efficiently produce CO that can further diffuse, couple, and reduce to form ethanol and other C2 or C3 products. The ethanol faradaic efficiency increased from 11% to 17% at 150 mA/cm², when switching from a pure copper catalyst to a layered catalyst consisting of 60% Cu and 40% Ag. More broadly the faradaic efficiency of all C2+ products reached a maximum value of 67% with this catalyst.

D3.2 - Report on Sniffer Chip discoveries relating to ethanol/ethylene branching mechanism

D3.3 - Report on recycle and temperature effects on ECO2R

D3.4 - Report on synchrotron measurements discoveries relating to ethanol/ethylene branching mechanism

D3.5 - Final report on WP achievements in terms of ECO2R selectivity to ethanol/acetaldehyde at high current density

D4.1 - Report on the impact of reaction intermediates on ECO2R selectivity towards ethylene

Electrochemical CO₂ reduction (ECO2R) on a copper catalyst leads to a wide product composition of various value-added chemicals such as CO, ethanol, and ethylene. A number of additional minor products have been reported, namely acetate, acetaldehyde, formate and glyoxal. These compounds are typically measured in only minor amounts of ~1% each. However, these compounds play an important role as reaction intermediates to some of the major product pathways that we would like to manipulate to steer product selectivity. This deliverable investigates the effects of these reaction intermediates on the experimental selectivity of ethylene, the targeted product for WP4.
Specifically, the controlled addition of reaction intermediates into an operational ECO2R system is performed for a number of crucial intermediates, and the resulting change in product selectivity measured. We find that the direct reduction of acetaldehyde and glyoxal in even minor concentrations at elevated current densities will shift electrons away from the target product ethylene. Measured ethanol and acetaldehyde concentrations indicate that this is also occurring during ECO2R without additives.
The conclusions from these results provide strategies to increase the selectivity of ethylene formation via glyoxal and acetaldehyde scavengers, which remove the intermediates prior to their subsequent reduction to alcohols. If successful, such a strategy may shift ~10% of electrons from the alcohol to hydrocarbon pathways.

D4.2 - Report on in-situ observations of catalyst structure and localized activity using electrochemical AFM system

D4.3 - Report on modifying catalyst layer thickness, morphology, surface structure for high efficiency ethylene production and suppression of competing reactions

D4.4 - Report on applying mass transport findings and new gas-diffusion electrodes for reducing H2 and C1 production

D5.1 - Benchmarking gas diffusion layers delivered to TUB, DTU, TUD

The use of Gas Diffusion Electrodes (GDEs) has been identified as a key tool to obtain an efficient CO2 electrochemical conversion to valuable chemicals. Work Package 5 will focus on obtaining an optimized GDE, which pass through the development of an optimized Gas Diffusion Layer (GDL, i.e. GDE without the catalytic layer) in order to achieve the performance targets.
Such development phase begins with the evaluation of the currently commercially available GDLs, in order to setting the basis and have a reference benchmark to start from. For this reason, commercial DeNora GDL for Fuel Cells (code DN908) was shipped to DTU, TUB, TUD and EPFL. The first three universities will deposit a reactive layer with benchmarking catalysts and test the commercial GDL performances, while EPFL will perform structural studies (3D Tomography) to evaluate the GDL features and support the mass transport model development.

D5.2 - Report on benchmark results of GDE from CO2 to carbon monoxide, ethanol and ethylene - CONFIDENTIAL

The deliverable describes the digitalization approach of the gas diffusion layer (GDL) and gas diffusion electrode (GDE). The adopted strategy consists of using computed tomography techniques of different resolutions and subsequent segmentation techniques, followed by the characterization and quantification of structural properties (porosity, surface area, homogeneity, anisotropy, pore and fibre size distributions). These structural details can then be used to guide optimization of the GDL and GDE for enhanced transport and, ultimately, enhanced device performance. Furthermore, this digitalization and characterization activity feeds into the pore-level simulations performed in WP7, and this interface is also described.

D5.3 - Report on approaches for optimization of GDL porous structure from digitalized GDE - CONFIDENTIAL

The deliverable describes the digitalization approach of the gas diffusion layer (GDL) and gas diffusion electrode (GDE). The adopted strategy consists of using computed tomography techniques of different resolutions and subsequent segmentation techniques, followed by the characterization and quantification of structural properties (porosity, surface area, homogeneity, anisotropy, pore and fibre size distributions). These structural details can then be used to guide optimization of the GDL and GDE for enhanced transport and, ultimately, enhanced device performance. Furthermore, this digitalization and characterization activity feeds into the pore-level simulations performed in WP7, and this interface is also described..

D5.4 - Supply 3 types of GDE with electrocatalysts selective for CO, ethylene and ethanol

D5.5 - Report on performances obtained from single cell testing of CO2 reduction with optimized GDE

D6.1 - Supply initial AEMs to DTU team for CO2 crossover screening. (2 sheets: 25 cm x 25 cm of each type) - CONFIDENTIAL

The aim of this deliverable was to supply initial batches of anion-exchange membranes (AEM) to the DTU-EX team to allow them to evaluate in small sized carbon dioxide electro-reduction (CO2ER) cells. The purpose of this is to allow a down-selection of thickness and head-group chemistry to reduce the number of variables that need to be considered when SURREY is developing the next generation of RG-AEMs (tailored specifically for CO2ER). Six different batches of RG-AEM were sent to DTU-EX. The deliverable report contains key characterisation data and initial life cycle analyses-relevant data for the RG-AEMs supplied.

D6.2 - Supply (2 g of each type) AEIs to TUB, DTU, and TUD for investigations into how different head-group chemistries affect the catalysis of the different CO₂ reduction pathways. - CONFIDENTIAL

The aim of this deliverable (WP6, D6.2) was to supply initial batches of (current generation) radiation-grafted anion-exchange ionomer (RG-AEI) to the DTU-EX, TUD, and TUB teams to allow them to evaluate how useful these ionomer powders will be in carbon dioxide electro-reduction (CO2ER) cells. This report contains key characterisation data and initial life cycle analyses-relevant data for the RG-AEIs supplied.

D6.3 - Supply initial amounts (5 sheets: 25 cm x 25 cm) of the next-generation AEMs (with co-monomer components) to DTU and small amounts of next-generation AEIs (500 mg) to catalyst WPs (for catalyst evaluation).

D6.4 - Supply of large batches of finalized (fully characterized) AEM (Minimum of 10 sheets: 25 cm x 25 cm) and AEIs (Minimum of 10 g batch) to project partners who require them.

D6.5 - Report on benchmarking of initial AEM’s

This deliverable demonstrates the effectiveness of US current-generation anion exchange membranes (AEM) with the following head groups (supplied in D6.1): trimethylamine (TMA), N-methylpyrrolidine (MPY), and (3) N-methylpiperidine (MPIP) in relation to a benchmark commercial Sustainion membrane. We tested for CO₂ electrolysis to CO using a standard Ag catalyst to allow the focus to be on the membranes. We tested for CO selectivity versus hydrogen, operating potential, ohmic resistance and CO₂ crossover in the membrane across a range of current densities 50-300 mA/cm2. We tested AEMS made from 25 µm and 50 µm thickness ETFE with only the 25 µm variants being effective. We also did long term studies of 24 hours and 200 hours. The end conclusion is that the US synthesized membranes are very competitive with the commercial Sustainion membranes with the MPIP membrane showing the most promise.

D6.6 - Report on optimized AEM’s and AEI’s

D7.1 - Library of digitalized porous electrodes - CONFIDENTIAL

The deliverable presents the methodology used for the digitalization of gas diffusion electrodes (and specifically the catalyst layers) and their quantitative structural characterization. It represents an (extendable) digital electrode library and specifically presents the three characteristic electrodes from the three partners involved in the catalyst design (TUD, TUB and DTU).

D7.2 - Developed pore-level transport model

D7.3 - Developed device model

D7.4 - Device model validation report

D7.5 - Parametrization of implicit solvent models against AIMD

D7.6 - Pathways towards CO, ethylene, ethanol on Cu facets

D7.7 - Determination of the impact of reaction conditions on ECR activity and selectivity towards high value products

D7.8 - Combining atom-, meso-, and device-scale models

D8.1 - Integrated analysis of the new technologies based on sustainability pillars and circularity analysis – baseline LCA/LCC/S-LCA

D8.2 - Conclusions on circularity potential of SELECTCO2 solution

D8.3 - Market analysis and opportunities for SELECTCO2 technology

D8.4 - SELECTCO2 benchmarking analysis with other CO₂ valorization techniques

D8.5 - Business models for the promotion of SELECT CO2 technology

The communication of the project will be unified along a common visual entity. A coherent visual chart (colours, fonts, designs) will be derived from the project logo and provided in several shapes and formats (document templates etc.). This visual identity will be used extensively throughout the project, creating a distinguishable brand that will be recognized by the various communities.

The SELECTCO2 project website is designed to fulfil project communication and dissemination needs for the benefit of the whole scientific community and the public through relevant information including: project overall objectives, partner & work packages information ; project activities: news, meetings ; project progress: technical publications, conference presentations, public domain reports ; project resources: links, related events … ; project contact information All the partners will collectively participate in the dissemination objective of the website by providing up-to-date information

D9.3 - Dissemination and knowledge management protocol - CONFIDENTIAL

This report presents the dissemination protocol for the SELECTCO2 project, the procedure for “Open Access” to peer reviewed research articles, internal rules, information on support from the EU members and the strategy for Knowledge Management within the project.

D9.4 - Organization of a SELECTCO2 dedicated symposium

D9.5 - Stakeholders Engagement Meeting

D9.6 - Survey of dissemination activities and final plan for dissemination and exploitation of project results