Research

The interest in preparing single atom catalysts is undeniable since they have become the most active new frontier in heterogeneous catalysis. SACs present well-defined active centres, such that unique opportunities exist for the rational design of new catalysts with high activity, selectivity and stability. However, preparing SACs with atomic precision is challenging due to the high surface energy and tedious synthetic procedures, which largely hinder their practical applications. Therefore, finding a suitable and effective method to synthesise and stabilise single atoms is an urgent requirement.

The INCAT group has recently started to work on this field trying to go a step further. We do not just propose an approach for the synthesis of SACs, but rather a complete and innovative method for controlling the SACs’ local environment and, therefore, their catalytic properties. In this way, we are working on two different approaches: (1) dual coordinated SACs, substituting one or more nitrogen atoms by other heteroatoms with lower electronegativity to adjust the electronic structure of the active sites; and (2) dual-metal atom catalysts to obtain a synergetic effect between the two metals to boost the activity.

For the desing, development and characterization of SACs, we usually collaborate with theoretical groups whose models provide crucial information about the SAC nanostructures with the most suitable electronic properties for boosting the catalytic activity.

A critical point in SACs’ development is their characterization. We used sophisticated experimental techniques, such as X-ray absorption spectroscopy (XAS) and high-angle annular darkfield scanning transmission electron microscopy (HAADF-STEM), combined with other techniques, such as X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS) and infrared spectroscopy (IR), as well as advanced modelling and simulation methods in computational chemistry .

Ask for more information to laura.calvillolamana@unipd.it 

Check some of our publications:

1. Copper single-atoms embedded in 2D graphitic carbon nitride for the CO2 reduction, npj 2D Mater. and Appl. 2021, 63.

2. Insights into the active nickel centers embedded in graphitic carbon nitride for the oxygen evolution reaction. J. Mater. Chem. A, 2024, 12, 6652 – 6662. 

3. Stabilization of copper porphyrin into carbon nitride for the photoelectrocatalytic reduction of CO2. J. Catal., 2024, 436, 115597.

Since the (re)discovery of Graphene in 2004 by Nobel Laureates A. Geim and K. Novoselov, Materials Science has constantly looked for new 2D materials with novel properties and applications.

The INCAT group has joined this research, focusing on the synthesis of new graphene derivatives obtained by wet chemistry protocols and on the study of their chemical properties in catalysis. We are particularly interested in activation of small molecules (O2 and CO2), selective oxidations, cross coupling reactions and photo induced reactivity, , all of them performed using Green Chemistry protocols. Moreover, we carefully combine these 2D materials with atoms, coordination complexes or nanoparticles to build even more advanced catalysts. 

We also exploit our expertise in Surface Science and Advanced characterization techniques to grow under ultra high vacuum conditions exotic 2D nanostructures such as Dirac Materials, Topological Insulators, metal chalcogenides and investigate their unique electronic and chemical properties.

Ask more information to stefano.agnoli@unipd.it or mattia.cattelan@unipd.it

Check some of our publications on this topic:

1. Palladium nanoparticles supported on graphene acid: a stable and eco-friendly bifunctional C–C homo-and cross-coupling catalyst Green Chem., 2019, 21, 5238-5247 Link to the abstract 

2. Combined high degree of carboxylation and electronic conduction in graphene acid sets new limits for metal free catalysis in alcohol oxidation Chem. Sci., 2019, 10, 9438-9445 Link to the abstract 

3. The nature of the Fe-graphene interface at the nanometer level, Nanoscale, 2015, 7, 2450 – 2460. Link to the abstract 

4. New Strategy for the Growth of Complex Heterostructures Based on Different 2D Materials, Chem. Mater. 2015, 27, 4105−4113 Link to the abstract 

Electrochemical energy conversion presents a promising pathway for addressing global energy and environmental challenges by enabling the sustainable transformation of carbon dioxide (CO₂) and water into value-added products. In particular, the electrochemical reduction of CO₂ (CO₂RR) and the hydrogen evolution reaction (HER) are two critical processes for producing carbon-neutral fuels and chemicals using renewable electricity. CO₂RR allows for the conversion of captured CO₂ into hydrocarbons or alcohols, potentially closing the carbon loop, while HER facilitates the generation of clean hydrogen fuel from water. These processes are central to the development of a circular carbon economy and the transition toward low-carbon energy systems. Ongoing research focuses on improving the efficiency, selectivity, and stability of electrocatalysts to make these technologies viable for large-scale application.

A growing area of interest is decoupled water splitting, which separates the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in time or space, often using redox mediators or solid-state electron storage materials. This approach offers several advantages, including improved energy efficiency, enhanced system flexibility, and better integration with intermittent renewable energy sources. By decoupling the anodic and cathodic processes, it becomes possible to tailor reaction environments for each half-cell, optimizing performance and stability. In addition, if OER is substituted by a more thermodynamically favorable oxidation reaction (hybrid decoupled water splitting), it is also possible to generate electricity during the redox mediator regeneration.

Ask for more information to laura.calvillolamana@unipd.it 

Check out some of our publications:

1. Copper single-atoms embedded in 2D graphitic carbon nitride for the CO2 reduction, npj 2D Mater. and Appl. 2021, 63.

2. Insights into the active nickel centers embedded in graphitic carbon nitride for the oxygen evolution reaction. J. Mater. Chem. A, 2024, 12, 6652 – 6662. 

3. Cobalt Spinel Nanocubes on Nitrogen Doped Graphene: a Synergistic Hybrid Electrocatalyst for Highly Selective Reduction of Carbon Dioxide to Formic Acid. ACS Catalysis 7, 2017, 7695–7703.

4. Operando Exploration of CoAl‐LDH: Transformations Driving Alkaline Oxygen Evolution Reaction. Small 2025, 2412351

Powering catalysis with sustainable and abundant solar energy will have a substantial impact on chemical industry, and thus artificial photocatalytic energy conversion provides a powerful strategy for the deployment of more sustainable industrial processes.

Our main research interests are the design, synthesis, and characterization of inorganic complexes and organic/inorganic nanomaterials: we develop novel homo- and hetero-geneous catalytic systems for light-powered reactions to produce solar fuels or commodity chemicals. 

We are currently interested in the semi-hydrogenation of acetylene to ethylene (research sponsored by our 2025 FIS grant). Ethylene, a key commodity chemical and starting material for ∼60% of all plastics, is commonly obtained by steam cracking together with ∼1 vol% acetylene impurity (poisonous to polymerization catalysts), which is usually removed by thermal hydrogenation.

We like to develop new catalytic platforms with the following advantages over the present thermal hydrogenation technology in industry:

(i) operation at room temperature using light in place of high temperatures;

(ii) use of water in place of an external hydrogen gas feed;

(iii) non-noble metal catalysts in place of nobel metal (Pd) catalysts.

For information, contact Francesca Arcudi (francesca.arcudi@unipd.it & Arcudi Lab).

Please have look at our latest works if you would like to know more: 

• Stone, A.; Fortunato, A.; Wang, X.; Saggioro, E.; Snurr, R.; Hupp, J.; Arcudi, F. (corr. author); Đorđević, L.; "Photocatalytic Semi-Hydrogenation of Acetylene to Polymer-Grade Ethylene with Molecular and Metal-Organic Framework Cobaloximes" Adv. Mater. 2025, 37, 2408658. https://doi.org/10.1002/adma.202408658

• Fortunato, A,; Perilli, D.; Dron, A.; Celorrio, V.; Dražić, G.; Ðorđević, L.; Calvillo, L.; Di Valentin, C.; Arcudi, F. (corr. author); "Selective semi-hydrogenation of acetylene using a single-atom cobalt on carbon nitride photocatalyst with water as a proton source" Chemrxiv, in revision, 2025. doi: 10.26434/chemrxiv-2025-1v585.

• Stone, A.; Ðorđević, L.; Stupp, S. I.; Weiss, E. A.; Arcudi, F. (corr. author); Hupp, J. T.* "Selective Photocatalytic Reduction of Acetylene to Ethylene Powered by a Cobalt-Porphyrin Metal–Organic Framework" ACS Energy Lett. 2023, 8, 11, 4684–4693. https://doi.org/10.1021/acsenergylett.3c01995

• Arcudi, F.; Ðorđević, L.; Schweitzer, N.; Stupp, S. I.; Weiss, E. A. "Selective visible-light photocatalysis of acetylene to ethylene using a cobalt molecular catalyst and water as a proton source" Nat. Chem. 2022, 14, 1007-1012. https://doi.org/10.1038/s41557-022-00966-5 

Advanced materials require an advanced characterization. This ambitious challenge has been tackled by the INCAT group through a constant innovation in materials analysis and thanks to collaborations with several specialized laboratories around the world.

Over the years, the INCAT team has acquired a unique expertise in the characterization of surfaces by means of electron spectroscopies, scanning probes and electrochemical techniques. 

In our labs, you can find three X-ray photoemission spectroscopy (XPS) instruments for qualitative and quantitative surface chemical analysis; we can look at single atoms on surfaces by scanning tunnel microscopy (STM), and understand surface reconstructions and resolve 2D ordered nanostructuctures by low energy electron diffraction (LEED).  

At the core of our scientific interests, there is the development of new synthetic routes for the preparation of exotic 2D materials, functional thin films and engineered heterostructures through physical and chemical vapor deposition.

We have also developed unique facilities for the study of electrocatalytic processeses such as an operando electrochemical cel for X-ray absorption spectroscopy experiments, a combined XPS spectrometer and flow jet electrochemical cell. The operando characterization is performed both on powders and model systems. We have also experience in following in situ the electrochemical reactions by differential electrochemical mass spectrometry (DEMS) and infrared spectroscopy (FTIR).

Recently, our team contributed to the advancement of scanning probe microscopies, proposing a new method to identify with atomic scale resolution electrocatalytic events through the analysis of the noise in the signal of electrochemical STM.

Moreover we have a great history of collaborations with synchrotron radiation facilities, especially with Elettra (Italy) but also Diamond (UK), PSI (Switzerland), NSLS II (USA), Max-Lab IV (Sweden).

Check some of our publications on this topic or ask more information to stefano.agnoli@unipd.it, mattia.cattelan@unipd.it, or laura.calvillolamana@unipd.it. 

1. Insights into the durability of Co–Fe spinel oxygen evolution electrocatalysts via operando studies of the catalyst structure.  J. Mater. Chem. A, 2018,6, 7034-7041 Link to the abstract 

2. The magnetization orientation of Fe ultrathin layers in contact with graphene Phys. Chem. Chem. Phys., 2016,18, 33233-33239 Link to the abstract

3. Atom-by-atom identification of catalytic active sites in operando conditions by quantitative noise detection Joule 2022, 6, 617-635 Link to the abstract 

4. Operando visualization of the hydrogen evolution reaction with atomic-scale precision at different metal–graphene interfaces Nat Catal, 2021, 4, 850-859 Link to the abstract