Research

SINGLE ATOM CATALYSTS (SACs)

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


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


2D MATERIALS

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.

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


  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

ADVANCED AND IN SITU CHARACTERIZATION

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.

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 or mattia.cattelan@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