Periodic Reporting for period 1 - LoCatSpot (Localized catalytic hotspot detection, manipulation, and creation for Energy Innovations) Reporting period: 2020-07-01 to 2022-06-30 Summary of the context and overall objectives of the project Throughout the European Union, questions about the sustainability of our lifestyles have become a strong motivation for innovation in science and industry. The transformation of our society from the use of fossil fuels to the use of renewable energy sources is fundamental and a major challenge. A study from the Fuel Cells and Hydrogen joint undertaking (FCH JU) points to hydrogen as an essential element in the energy transition. The report “Hydrogen Roadmap Europe: A sustainable pathway for the European Energy Transition” says that hydrogen can account for 24% of final energy demand and 5.4 million jobs by 2050. Hydrogen can be produced by electrochemical water splitting. Tremendous efforts have already been made to develop new materials for efficient electrochemical water electrolysis. Since the first isolation of single-layer graphene, 2D layered materials have had an important role in related innovations. Among the 2D materials, transition metal dichalcogenides (TMDs) attracted great interest as potent electrocatalysts for the hydrogen evolution reaction (HER). However, up to now the expectations of TMDs as a possible replacement for less abundant Pt-based HER catalysts have not been fulfilled. On the road to better TMD-based catalysts for HER several challenges have to be faced. The first challenge is the gathering of specific information about the electrochemical activity of surface features. The second challenge is the selective generation and modification of well-defined TMD structures. The scanning electrochemical microscopy (SECM) provides the ideal basis for overcoming these challenges, by enabling the localization of catalytic effects on individual surface features as well as the generation of well-defined TMD structures. Therefore, this project entails the application of localized electrochemistry for selective electrochemical deposition and the direct analysis of the HER activity of TMDs to link the local electrochemical activity with structural features. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far The report covers the whole period of the project. Following the proposed work packages, the project started with electrochemical investigations (macroscopic and microscopic) of novel electrode materials such as 3D printed electrodes and the examination of the HER activity at different electrodeposited TMDs (MoS2, WS2, MoS2/WS2) by SECM.1) C. Iffelsberger, C.W. Jellett, M. Pumera, 3D Printing Temperature Tailors Electrical and Electrochemical Properties through Changing Inner Distribution of Graphite/Polymer, Small. 17 (2021) 2101233. 2) C. Iffelsberger, S. Ng, M. Pumera, Photoelectrolysis of TiO2 is highly localized and the selectivity is affected by the light, Chem. Eng. J. 446 (2022) 136995. 3) K.A. Novčić, C. Iffelsberger, S. Ng, M. Pumera, Local electrochemical activity of transition metal dichalcogenides and their heterojunctions on 3D-printed nanocarbon surfaces, Nanoscale. 13 (2021) 5324–5332. In the second stage, the localized electrochemical deposition of MoSx as a model catalyst material for HER was performed and its further development resulted in the electrochemical printing of microstructured, for HER highly active, MoSx with controlled chemical composition in a one-step process using the SECM. 4) C. Iffelsberger, M. Pumera, High resolution electrochemical additive manufacturing of microstructured active materials: Case study of MoSxas a catalyst for the hydrogen evolution reaction, J. Mater. Chem. A. 9 (2021) 22072–22081. In the following the direct formation of MoSx catalyst material inside an operating flow cell directly followed by the continuous monitoring of the catalyst’s activity under operational (flow) conditions was demonstrated.5) C. Iffelsberger, S. Wert, F.M. Matysik, M. Pumera, Catalyst Formation and in Operando Monitoring of the Electrocatalytic Activity in Flow Reactors, ACS Appl. Mater. Interfaces. 13 (2021) 35777–35784. Exploitation and dissemination: The results listed above have been or will be communicated to the research community via publications in journals. The expected training and the various scientific and transferable skills to be developed were successfully achieved. Interdisciplinary knowledge transfer from the fellow to the host resulted in several co-authored articles. Further publications are expected.6) K.A. Novčić, C. Iffelsberger, M. Pumera, Local electrochemical activity of transition metal dichalcogenides and their heterojunctions on 3D-printed nanocarbon surfaces, Nanoscale, 2021,13, 5324-5332.7) J. Muñoz, C. Iffelsberger, E. Redondo, M. Pumera, Design of Bimetallic 3D-printed Electrocatalysts via Galvanic Replacement to Enhance Energy Conversion Systems, Applied Catalysis B: Environmental, accepted.8) K. Ghosh, S. Ng, C. Iffelsberger, M. Pumera, 2D MoS2/carbon/polylactic acid filament for 3D printing: Photo and electrochemical energy conversion and storage, Appl. Mater. Today. 26 (2022). 9) M. Urso, C. Iffelsberger, C.C. Mayorga-Martinez, M. Pumera, Nickel Sulfide Microrockets as Self-Propelled Energy Storage Devices to Power Electronic Circuits “On-Demand,” Small Methods. 5 (2021) 1–9. 10) S. Wert, C. Iffelsberger, K.A. Novčić, F.M. Matysik, M. Pumera, Edges are more electroactive than basal planes in synthetic bulk crystals of TiS2 and TiSe2, Appl. Mater. Today. 26 (2022). 11) C. Iffelsberger, D. Rojas, M. Pumera, Photo-Responsive Doped 3D-Printed Copper Electrodes for Water Splitting: Refractory One-Pot Doping Dramatically Enhances the Performance, J. Phys. Chem. C. (2022).12) W. Gao, C. Iffelsberger, M. Pumera, Dual polymer engineering enables high-performance 3D printed Zn-organic battery cathodes, Appl. Mater. Today. 28 (2022) 101515. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) This project effectively pushed the state-of-the-art in terms of localized electrochemical investigations of novel electrode materials for the electrochemical energy conversion (such as HER) and beyond. We have demonstrated that the controlled localized generation of electrochemical catalysts can be used for high-resolution electrochemical additive manufacturing (electrochemical printing) to overcome the important limitation of low activity. Therefore, the work showed a novel and promising approach to the on-demand fabrication of electrochemical devices. Due to the general versatility of the localized electrodeposition processes, an extension of the presented method to other materials important for energy conversion and storage to produce electrochemical devices is now conceivable. Additionally, it was shown that the proposed method offers unique opportunities to synthesize active materials with highly localized morphological and chemical variations which open another door to improved catalyst materials and pave the way for the on-demand construction of unprecedently effective electrochemical devices. Finally, the localized formation and direct characterization of the activity of the catalyst inside an operating flow reactor demonstrated the fascinating possibility for the detailed investigation of chemical processes in operating flow reactors. Therefore, the results of this project present important steps forward that are imperative for the successful evolution of electrochemical additive manufacturing devices to real-world applications. In conclusion, this project has been very successful and has resulted in a number of high-impact publications as well as international collaboration within Europe. locatspot.jpg
