Dr. Ioannis Spanos - Electrochemistry
- Dr. Ioannis Spanos
- Group leader
- Electrochemistry
- +49 (0)208 306 - 3845
- ioannis.spanos(at)cec.mpg.de
- Room: 672
Vita
| BSc. Physics | University of Patras, Greece (2006) | ||
| M.Sc. Environmental Sciences | University of Patras, Greece (2009) | ||
| Research Assistant | University of Patras, Greece (2009-2011) | ||
| Ph.D in Nanochemistry | University of Copenhagen, Denmark (2014) | ||
| Research Assistant | University of Copenhagen, Denmark (2014-2015) | ||
| Postdoc | MPI CEC (2015-2020) | ||
| Group leader | MPI CEC (seit 2020) | ||
Publications
Full publications list | ORCID | ResearcherID | Google Scholar Profile
Newest Publications
2025
K Ham, S Albarqawi, SM El‐Refaei, A Lim, I Spanos* (2025) Probing the Effect of Spectator Anions on Chloride Adsorption for Selective Oxygen Evolution Reaction over Ni Catalysts ChemElectroChem 13 (1), e202500387
A Olean-Oliveira, AR Khan, B Toplak, I Spanos, M Hammad, A Jain, U Hagemann, H Wiggers, D Segets, V Čolić (2025) Intrinsic Activity and Mechanistic Insights in LaCoO₃ OER Catalysts Induced by Support Material Electrochimica Acta, 147874
D Simondson, MF Tesch, I Spanos, TE Jones, J Guo, BV Kerr, M Chatti, S A Bonke, R Golnak, B Johannessen, J Xiao, D R MacFarlane, R K Hocking, A N Simonov (2025) Decoupling the catalytic and degradation mechanisms of cobalt active sites during acidic water oxidation Nature Energy 10 (8), 1013-1024
A Lim, K Ham, T Quast, S Lee, MF Tesch, S Czioska, D Ramermann, W Hetaba, W Schuhmann, J-D Grunwaldt, S K Cho, H-Y Park, J H Jang, S H Ahn, I Spanos*, H S Park (2025) Limited Surface Oxide Growth as a Prerequisite for Stabilizing Low-Loading Iridium Electrodes for PEM Water Electrolysis ACS Catalysis 15 (8), 6098-6113
2024
V Vinayakumar, T Wagner, C Marcks, J Johny, G Wartner, MF Tesch, I Spanos, A Ghafari, A Jain, O Prymak, I Sanjuán, A S Odungat, O Anwar, M Chatwani, A Jose, V Chanda, A Knop-Gericke, C Andronescu, A K Mechler, N Wöhrl, D Segets (2024) Ni-Co-O anodes for the alkaline oxygen evolution reaction: Multistage electrode optimization and plasma-assisted activity enhancement enabled by a coherent workflow Chemical Engineering Journal 523 (2025) 167169
A Olean-Oliveira, N Hasnain, R Martinez-Hincapie, U Hagemann, A Jain, D Segets, I Spanos, V Colic (2024) Electrochemical Insights into Hydrogen Peroxide Generation on Carbon Electrodes: Influence of Defects, Oxygen Functional Groups, and Alkali Metals in the Electrolyte ACS Catalysis 14 (23), 17675-17689
A Lim, K Ham, S Elrefaei, I Spanos* (2024) Operando interpretation of reaction mechanisms and local phenomena on OER catalysts in seawater electrolysis Current Opinion in Electrochemistry 47, 101560
AR Zeradjanin, A Lim, I Spanos, J Masa (2024) What Limits Conquest of Stability Descriptors?–Intriguing Aspects of Dissolution of Oxygen Evolution Electrocatalysts ChemElectroChem 11 (12), e202300832
S El-Refaei, D L Rauret, A G Manjón, I Spanos, A Zeradjanin, S Dieckhöfer, J Arbiol, W Schuhmann, J Masa, (2024) Ni-Xides (B, S, and P) for alkaline OER: shedding light on reconstruction processes and interplay with incidental fe impurities as synergistic activity drivers ACS Applied Energy Materials 7 (4), 1369-1381
Research 'Electrochemistry'
Short Profile / Mission Statement
Water electrolysis is a chemically dynamic interfacial process rather than a static catalytic reaction. Our research deciphers how catalyst structure, reactive intermediates, trace impurities, and electrolyte chemistry evolve under realistic operating conditions — and how these transformations govern activity, stability, and selectivity.
Research Topics
Operando Multi-Method Correlation
Understanding electrocatalytic performance requires more than polarization curves. We combine time-resolved operando spectroscopy (Raman, SERS), Quick-XAS, electrogravimetry (eQCM), and dissolution analytics (ICP-OES) to simultaneously monitor surface chemistry, oxidation state, mass changes, and leaching under reaction conditions.
Trace Impurities as Design Variables
What has long been dismissed as contamination often dictates true catalyst behavior. Trace Fe³⁺ incorporates into Ni-based oxyhydroxides enhancing activity, while organic amines from membranes bind to active sites and suppress beneficial processes. We classify impurity effects into interfacial (adsorption) vs incorporative (lattice integration) pathways and show how they reshape structure–function relationships.
Reactive Oxo-Species in Iridium Oxides
In acidic media, dynamically formed μ-oxo species and local structural contraction determine both reversible activation and irreversible degradation of IrOx catalysts. Using operando spectroscopic fingerprints, we link these structural motifs to activity descriptors and regeneration pathways.
Electrolyte and Selectivity Control in Chloride-Rich Media
Low-quality and saline waters introduce competing pathways such as chlorine evolution and hypochlorite formation. By tracking local pH, transient anion adsorption, and surface vibrational signatures, we identify key factors controlling selectivity and corrosion risk in chloride-rich environments.
Methods and Techniques
Our research infrastructure integrates:
Selected Publications
Iridium Oxide Deactivation and Regeneration Mechanisms
(Phys. Chem. Chem. Phys., DOI:10.1039/D2CP00828A)
We decoupled reversible and irreversible routes of IrOx performance change under acidic OER. Potentiodynamic cycling yields reversible activity loss recoverable through cathodic reduction, whereas potentiostatic operation leads to irreversible condensation-driven degradation, establishing electrochemical signatures of mechanistic failure pathways.
Low-Loading Iridium Electrode Design
(ACS Catalysis, DOI:10.1021/acscatal.4c07864)
This work demonstrates how nanoscale engineering of iridium oxide layers on conductive supports achieves high OER activity at ultra-low loadings while mitigating dissolution. The study balances precious metal utilization with structural durability, offering design criteria for efficient acidic electrolyzer catalysts.
Complex materials in electrocatalysis (e.g. metal-metalloid alloys)
Non-Metal Dopants, Fe Uptake, and Ni-Based Reconstruction
(ACS Applied Energy Materials, DOI:10.1021/acsaem.3c03114)
We show how non-metal dopants (B, P, S) influence surface reconstruction and interplay with incidental Fe uptake in Ni oxides. The work reveals how dopant identity and impurity interactions jointly shape kinetics and stability in alkaline OER, highlighting the need for electrolyte control in catalyst screening.
Anion-Controlled Selectivity in Chloride-Rich Electrolytes
(ChemElectroChem, DOI:10.1002/celc.202500387)
Through combined eQCM and SERS, we decipher how spectator anions modulate chloride adsorption and interfacial chemistry during oxygen evolution. The study identifies how electrolyte composition affects competing reaction pathways, especially relevant for seawater and saline electrolysis environments.
Projects
DERIEL (De-Risking Electrolyzers)
Within DERIEL (2022–2025), we apply operando X-ray absorption spectroscopy (XAS), surface-enhanced Raman spectroscopy (SERS), electrochemical quartz crystal microbalance (eQCM), and ICP-OES in concert with electrochemistry to resolve dynamic restructuring and dissolution pathways of iridium-based OER catalysts under realistic operating conditions.
MAXNET
Within the MAXNET Energy initiative of the Max Planck Society, our research contributes to understanding structure–function relationships in electrocatalytic water splitting. By resolving impurity-driven activation, degradation mechanisms, and electrolyte effects, this work supports the development of durable, resource-efficient catalyst systems for sustainable hydrogen production.
