Nanostructure electrodeposition and electrocatalysis – Sebastián-Pascual group
Clean energy conversion devices, such as electrolysers and fuel cells, convert electricity into chemicals and vice versa through electrocatalytic reactions. Searching for new materials to efficiently catalyse reactions at the electrified interface is key for the implementation of these devices.
I am starting a new group in experimental electrochemistry. I have experience in the preparation of nanostructured materials via electrodeposition technique and in the electrochemical characterization of model extended surfaces, such as polycrystalline and atomically well-ordered single facets. Studies on single facets have shown that both activity and product formation in electrocatalysis is strongly affected by the catalyst surface structure. In my group, we will combine studies on model extended surfaces and electrodeposition methods, to rationally prepare nanostructured catalysts with tuned surface structure and composition for electrocatalysis. The aim of my group will be to find which electrochemical conditions (e.g. applied potential conditions, electrolyte…) and which catalyst structures enable the production of renewable chemicals more efficiently.
1) Electrodeposition of nanostructures.
Here we investigate the applicability of green solvents, such as deep eutectic solvents (DES) and/or other ionic liquids, to prepare nanostructured materials using electrodeposition technique. Our research aims to assess both solvent and substrate effects on the first stages and growth of the deposited nanostructures.
2) Electrochemical characterization of model surfaces.
Electrocatalytic reactions are affected by the active site´s geometry and surface structure. Here we experimentally characterise atomically well-ordered single facets or single crystalline electrodes aiming to understand how the surface ordering and orientation affect electrochemical processes.
3) Electrochemical CO and CO2 reduction.
Here we aim to investigate how the electrode-electrolyte interface or electric double layer structure influences the CO and CO2 conversion towards fuels and chemicals. We carry out potential controlled experiments on both well-defined single crystalline electrodes and nanostructured Cu electrodes with tuned distribution of facets.
4) Electrocatalysis of oxidation reactions
In a CO2-conversion electrolyser, the CO2 molecules are reduced at the cathode and water is typically oxidized to oxygen at the anode. The water oxidation or oxygen evolution reaction (OER) requires high applied overpotentials and usually scarce precious metals are used as catalysts.
Here we aim to: 1) prepare nanostructured OER catalysts and assess which parameters (metal loading, surface morphology, composition, applied potential…) affect both material´s stability and rate. 2) Investigate model oxidation reactions of small organic molecules, such as the oxidation of formic acid oxidation for low-temperature fuel cells. 3) Investigate the oxidation of bigger and more complex molecules which consumes less energy than OER, e.g., the oxidation of organic molecules from biomass.
List of publications:
- Ganassin, A.; Sebastian, P.; Climent, V.; Schuhmann, W.; Bandarenka, A. S.; Feliu, J., On the pH dependence of the potential of maximum entropy of Ir(111) electrodes. Scientific Reports, 7 (2017) nº DOI: 10.1038/s41598-017-01295-1.
- Ledezma Yanez, I.; Wallace, W. D. Z.; Sebastián-Pascual, P.; Climent, V.; Feliu, J. M.; Koper, M. T. M., Interfacial water reorganization as a pH-dependent descriptor of the hydrogen evolution rate on platinum electrodes. Nature Energy, 2 (2017) nº17031. DOI: 10.1038/nenergy.2017.31.
- Sebastian, P.; Giannotti, M. I.; Gómez, E.; Feliu, J. M., Surface sensitive nickel electrodeposition in deep eutectic solvent. ACS Applied Energy Materials, 1 (2018) 1016-1028. DOI:10.1021/acsaem.7b00177.
- Sebastián-Pascual, P.; Escudero-Escribano, M., Addressing the Interfacial Properties for CO Electroreduction on Cu with Cyclic Voltammetry. ACS Energy Letters, 5, 1 (2020) 130-135. DOI: 1021/acsenergylett.9b02456.
- Sebastian-Pascual, P.; Sarabia, F. J.; Climent, V.; Feliu, J. M., Escudero-Escribano, M. Elucidating the Structure of the Cu-Alkaline Electrochemical Interface with the Laser-Induced Jump Temperature Method. Journal of Physical Chemistry C, 124 (42) (2020) 23253–23259. DOI: 1021/acs.jpcc.0c07821.
- Landa-Castro, M.; Sebastián, P.*; Giannotti, M. I.; Serrà, A.; Gómez, E. Electrodeposition of Nanostructured Cobalt Films from a Deep Eutectic Solvent: Influence of the Substrate and Deposition Potential Range.Electrochimica Acta (2020), 136928. DOI: 10.1016/j.electacta.2020.136928.
- Sebastián-Pascual, P.; Petersen, A. S.; Bagger, A.; Rossmeisl, J.; Escudero-Escribano, M., PH and Anion Effects on Cu–Phosphate Interfaces for CO Electroreduction. ACS Catalysis, 11 (2021) 1128–1135. DOI: 10.1021/acscatal.0c03998.
- Plaza-Mayoral, E. ; Sebastián Pascual, P.*; Dalby, K. N.; Degn Jensen, K.; Chorkendorff, I.; Falsig, H.; Escudero-Escribano, M.*, Preparation of High Surface Area Cu-Au Bimetallic Nanostructured Materials by Co-Electrodeposition in a Deep Eutectic Solvent. Electrochimica Acta, 398 (2021) DOI:10.1016/j.electacta.2021.139309.
- Sebastián-Pascual, P.*; Escudero-Escribano, M.*, Surface characterization of copper electrocatalysts by lead underpotential deposition. Journal of Electroanalytical Chemistry, 896 (2021), DOI: 10.1016/j.jelechem.2021.115446.
- Plaza-Mayoral, E.; Jordão Pereira, I.; Nicole Dalby, K.; Degn Jensen, K.; Chorkendorff, I.; Falsig, H.; Sebastián-Pascual*, P.; Escudero-Escribano, M.*, Pd-Au nanostructured electrocatalysts with tunable compositions for formic acid oxidation. ACS Applied Energy Materials, 5, 9 (2022) 10632–10644. DOI: 1021/acsaem.2c01361.
Paula Sebastián Pascual
I am Assistant Professor at the Department of Chemistry -University of Copenhagen, financed by a DFF-project, since November 2022. In 2023, I have been granted a Villum Young Investigator grant to establish a research group in Electrochemistry.
We are looking for highly motivated Postdoctoral researcher, PhD, MSc and Bachelor students. Contact Paula Sebastian for further information.