Here is a selection of recent scientific papers I (co-)authored. A complete list can be found on my Google Scholar. All code that led to published works can be found on my GitHub.
On the crystal structure of nanoparticles
Modern electrocatalysts for the oxygen reduction reaction in a hydrogen fuel cell are commonly composed of platinum-alloy nanoparticles on a carbon support. Their varied structures mean they degrade differently under operating conditions. Understanding which structural features do and don’t influence activity or stability helps focus research on what truly improves catalyst performance.
At the atomic scale, platinum and copper atoms may be randomly mixed or arranged in an ordered structure. We found that ordered sites near the particle surface, where the reaction occurs, are more stable when preparing the catalyst for long-term use. This was possible with a new approach that combines identical-location 4D-STEM with unsupervised learning.
Structure–Stability Relationships in Pt-Alloy Nanoparticles Using Identical-Location Four-Dimensional Scanning Transmission Electron Microscopy and Unsupervised Machine Learning.
A.R. Kamšek et al, ACS Nano, 19 (2), 2334–2344, 2025.
Within the ordered phase, defects known as anti-phase boundaries can form, as previously seen in bulk alloys. In this work, we confirmed they also appear in nanoparticles, but found no effect on the catalytic activity.
Periodic anti-phase boundaries and crystal superstructures in PtCu₃ nanoparticles as fuel cell electrocatalysts.
A.R. Kamšek et al, Materials Today Nano, 23, 100377, 2023.
We showed how identical-location microscopy tracks the local history of platinum-cobalt nanoparticles, which complements the bulk information from other methods like electrochemical measurements.
The first paper compares commercial electrocatalysts for the oxygen reduction reaction in acidic media, and the second is a detailed investigation of platinum-cobalt nanoparticles at the atomic scale.
Resolving the nanoparticles’ structure–property relationships at the atomic level: a study of Pt-based electrocatalysts.
L.J. Moriau et al, iScience, 24 (2), 102102, 2021.
Observing, tracking and analysing electrochemically induced atomic-scale structural changes of an individual Pt–Co nanoparticle as a fuel cell electrocatalyst by combining complementary electron microscopy techniques.
A. Hrnjić et al, Electrochimica Acta, 388, 138513, 2021.
Atomically resolved microscopy images hold far more detail than the human eye can process. This review explains how computer algorithms can unlock that hidden information, providing objective insights and enabling the analysis of electrocatalyst image datasets too large or too tricky for manual work.
Bringing into play automated electron microscopy data processing for understanding nanoparticulate electrocatalysts’ structure–property relationships.
A.R. Kamšek et al, Current Opinion in Electrochemistry, 35, 101052, 2022.
What about the support?
The performance of electrocatalysts with supported nanoparticles can be improved not only by optimizing the noble-metal-based nanoparticles, but also by tailoring the support. Certain supports, such as ceramics, can interact with nanoparticles in ways that improve the catalytic performance.
These three papers are examples of how using a titanium oxynitride support created beneficial metal–support interactions for reactions in hydrogen fuel cells and water electrolyzers.
Metal–support interaction between titanium oxynitride and Pt nanoparticles enables efficient low-Pt-loaded high-performance electrodes at relevant oxygen reduction reaction conditions.
A. Hrnjić et al, ACS Catalysis, 14 (4), 2473–2486, 2024.
Titanium oxynitride-supported Ru nanoparticles as exceptional electrocatalysts for alkaline hydrogen evolution reaction.
M. Smiljanić et al, Chemical Engineering Journal, 164204, 2025.
Iridium Stabilizes Ceramic Titanium Oxynitride Support for Oxygen Evolution Reaction.
G. Koderman Podboršek et al, ACS Catalysis, 12 (24), 15135–15145, 2022.
Beyond electrocatalysis
These two papers step outside my usual focus on hydrogen technologies.
The first explores electrocatalytic CO₂ reduction, a carbon capture and utilization technology. Copper catalysts speed up the reaction, but their structural changes during operation affect long-term performance.
The second examines Ni-rich NMC, a commercial battery cathode material. It proposes a methodology for reliable, accurate impedance measurements of active electrodes and meaningful interpretation of the results.
Deactivation of copper electrocatalysts during CO₂ reduction occurs via dissolution and selective redeposition mechanism.
B. Tomc et al, Journal of Materials Chemistry A, 13 (6), 4119–4128, 2025.
Novel Methodology of General Scaling-Approach Normalization of Impedance Parameters of Insertion Battery Electrodes – Case Study on Ni-Rich NMC Cathode: Part I. Experimental and Theoretical Insights.
M. Firm et al, Journal of The Electrochemical Society, 171 (12), 120540, 2024.
