Metal-oxide nanosystems for electrodes in hydrogen fuel cells and photoelectrolyzers

In the framework of clean energy carriers and energy storage systems, hydrogen emerges as an opportunity, that however still requires the implementation of optimized electrochemical devices both for its green production via photo-electrolyzers and for its conversion via fuel cells. Moreover, several parts of these devices exploit critical raw materials, that must be substituted for a more sustainable industrial production, in terms of cost reduction, availability of elements and durability. A class of materials that fulfill all these requirements are metal oxides, in particular reducible metal oxides eventually coupled with metals in form of dopants, nanoparticles or single atom catalysts.

Our research focuses on the study of the electronic and optical properties of metal oxide films and nanostructures obtained by physical methods. These systems are versatile and allow the modification of the optical and catalytic response by tuning the coupling with metals. By means of electron spectroscopies, scanning probe microscopies, optical characterization both of steady state and of out-of-equilibrium photoexcited states (both at our NANO laboratory on-site and at large scale facilities with many active collaborations), we investigate the modifications induced in the materials, the role of the oxide and of the metal atoms/nanoparticles, the interaction with the surface for hydrogen dissociation or water splitting.

Figure 1: (a) Ag nanoparticles aggregated and deposited on CeO2 films; (b) False color transient absorbance map and spectra (lower panel) relative to the photoexcitation of CeO2 film, the arrows highlight the shift of the photoinduced absorption band during the first picosecond due to polaron formation; (c) Ambient pressure XAS spectra of Cu:CeO2 film during exposure to H2, indicating strong reduction of the oxide due to H2 dissociation.

PeopleStefania Benedetti, Sergio D’Addato, Alessandro di Bona, Paola Luches*, Eleonora Spurio
KeywordsHydrogen, oxide films, metal nanoparticles, electronic properties, ultrafast spectroscopies.
Methods, techniquesXPS, XAS, STM, SEM, XRD, FTAS, pump-probe XAS.
Granted projects2022-2025 (PNRR Next Generation EU) Ecosystem For Sustainable Transition In Emilia-Romagna ECOSISTER – Spoke 1

2022-2025 (PNRR Next Generation EU) National Centre for Sustainable Mobility CNMS – Spoke 11
CollaborationsRita Magri (Università di Modena e Reggio Emilia), Annabella Selloni (Princeton University, New Jersey, United States), Federico Boscherini (Università di Bologna), D. Catone , P. O’Keeffee (CNR-ISM Roma), Piero Torelli (CNR-IOM, Trieste), E. Principi (ELETTRA, Trieste), C. Milne (Eu-XFEL, Schenefeld, Germany).
A. Vikatakavi, S. Benedetti, G. Righi, R. Magri, S. D’Addato, P. Luches, A. Selloni. Interaction of hydrogen with Cu-modified cerium oxide surfaces. J. Phys. Chem. C 2022
J.S. Pelli Cresi, E. Spurio, L. Di Mario, P. O’Keeffe, S. Turchini, S. Benedetti, G.M. Pierantozzi, A. De Vita, R. Cucini, D. Catone, P. Luches. Lifetime of photo-generated positive charges in hybrid cerium oxide-based material from space and mirror charge effects in time-resolved photoemission spectroscopy. J. Phys Chem C 2022
M. Sygletou, S. Benedetti, M. Ferrera, G.M. Pierantozzi, R. Cucini, G. Della Valle, P. Carrara, A. De Vita, A. di Bona, P. Torelli, D. Catone, G. Panaccione, M. Canepa, F. Bisio. Quantitative Ultrafast Electron-Temperature Dynamics in Photo-Excited Au Nanoparticles. Small 2021
J.S. Pelli Cresi, E. Principi, E. Spurio, D. Catone, P. O’Keeffe, S. Turchini, S. Benedetti, A. Vikatakavi, S. D’Addato, R. Mincigrucci, L. Foglia, G. Kurdi, I. P. Nikolov, G. de Ninno, C. Masciovecchio, J. Kopula Kesavan, F. Boscherini, P. Luches. Ultrafast Dynamics of Plasmon-Mediated Charge Transfer in Ag@CeO2 studied by Free Electron Laser time-resolved X-ray Absorption Spectroscopy. Nano Letters 2021
J.S. Pelli Cresi, L. Di Mario, D. Catone, F. Martelli, A. Paladini, S. Turchini, S. D’Addato, P. Luches, P. O’Keeffe. Ultrafast formation of small polarons and the optical gap in CeO2. J. Phys. Chem. Lett. 2020
S. Benedetti, G. Righi, P. Luches, S. D’Addato, R. Magri, A. Selloni. Surface Reactivity of Ag-Modified Ceria to Hydrogen: A Combined Experimental and Theoretical Investigation. ACS Applied Materials & Interfaces, 2020
J.S. Pelli Cresi, E. Silvagni, G. Bertoni, M.C. Spadaro, S. Benedetti, S. Valeri, S. D’Addato, P. Luches. Optical and electronic properties of silver nanoparticles embedded in cerium oxide.  J. Chem. Phys. 2020
J.S. Pelli Cresi, M.C. Spadaro, S. D’Addato, S. Valeri, S. Benedetti, A. di Bona, D. Catone, L. Di Mario, A. Paladini, G. Bertoni, P. Luches. Highly efficient plasmon-mediated electron injection into cerium oxide from embedded silver nanoparticles. Nanoscale 2019
Conferences (invited)Paola Luches Dynamics of charge excitations in metal-oxide nanostructures for energy conversion.
107° Congresso Nazionale Società Italiana di Fisica, 13-17/09/2021.
Paola Luches Plasmonic nanoparticles coupled with oxides: dynamics of charge excitations,
in Recent developments in Gas Phase Synthesis of Nanoparticles and applications, CMD 29, 15/09/2021
* Contact person: