Nanoporous 3d metal-based catalysts

Previous and Current Research

The main idea is to develop cost-effective electrocatalysts and advanced electrode materials on the base of nanoporous (np) non-noble metals and alloys by vapour phase dealloying (VPD) using as-quenched M‑Zn precursors (M = Cu, Co, Ni and Fe). The composition, microstructure and morphology of the as-quenched ribbons as well as the parameters of the VPD process are investigated to control the morphology of the resulting np-materials. The electrochemical behaviour of the porous metals and alloys is studied to develop a process of residual Zn elimination as well as controllable oxidation/modification of their surface. The activity of obtained materials towards the carbon dioxide reduction reaction (CO2RR), the oxygen reduction reaction (ORR), the oxygen evolution reaction (OER), and the hydrogen evolution reaction (HER) are investigated to tailor their microstructure, morphology, phase, and chemical composition.

The previous research was focused on the impact of the nature and content of 3d transition metal on the formation of the structure of Al-based liquid alloys. The presence of chemical short-range order in the melts was shown. The interrelation between the local atomic structure of Al-based melts and the corresponding crystalline, quasicrystalline phases was established. It consists of the preservation of the main features of the chemical short-range order and poly-tetrahedral atomic packing. The presence of these clusters in the liquid binary and ternary Al-based alloys with TM may be a precondition for the formation of quasicrystalline phases and their crystalline approximants.

The influence of the silicon addition and nature of the TM on the formation of the amorphous phase during rapid solidification of the Al-Si-TM (TM = Mn, Fe, Co, Ni) melts has been established. It has also been shown that the structure data can be effectively used to choose types of associates for simulations of the liquid state within the framework of calculating phase diagrams by the CALPHAD method.

COLLABORATIONS

Department of Crystallization, Institute for Metal Physics of the NAS of Ukraine, Ukraine

Laboratory 14/1 «Studies of surface phenomena and synthesis of nanostructured materials», V. Bakul Institute for Superhard Materials of the NAS of Ukraine, Ukraine

Department of Metal Physics, Institute of Physics of the SAS, Bratislava, Slovak Republic

Donbas State Engineering Academy

PROJECTS

Grant of the President of Ukraine to support the research of young scientists No GP/F11/0030. (2006).

The Russian Foundation for Basic Research No. 10-03-90900. (2010).

SAIA grant, National Scholarship Programme of the Slovak Republic “The structure of liquid, solid and quenched Al-based alloys as a basis for the development of new advanced materials” (2016-2017)

State Research Project “Nanoporous 3d metal-based catalysts” No 0122U001910 (2022 - present).

Methodological and Technical Expertise

• High-temperature X-ray diffraction study

• X-ray powder diffraction

• Scanning electron microscopy

• Transition electron microscopy

• Molecular dynamic and reverse Monte-Carlo simulations of disordered systems

Selected Publications

1. I. Pozdnyakova, O. Roik, A. Bytchkov, F. Kargl, S. Jahn, S. Brassamin, G. N. Greaves, L. Hennet, Structure of levitated Si-Ge melts studied by high-energy x-ray diffraction in combination with reverse Monte Carlo simulations. J. Phys.: Condens. Matter 33 (2021) 244002 . https://doi.org/10.1088/1361-648X/abf593

2. O.S. Roik, O.M. Yakovenko, V.P. Kazimirov, V.E. Sokol’skii, N.V. Golovataya, Ya.О. Kashirina, Structure of liquid Al-Sn alloys. J. Mol. Liq., 330 (2021) 115570 https://doi.org/10.1016/j.molliq.2021.115570

3. O.S. Roik, V.P. Kazimirov, O.M. Yakovenko, V.E. Sokolskii, N.V. Golovataya, T.M. Mika, G.M. Zelinskaya Structure of liquid Al-Ge-Ni melts in a wide composition range, J. Mol. Liq., 293 (2019) 111458

https://doi.org/10.1016/j.molliq.2019.111458

4. J. Zigo O. Roik, P. Svec, M. Mihalkovic, P. Svec Jr, I. Matko, Study of the Al-T-Si (T= Fe, Co, Ni) alloys in the solid, liquid and as-quenched states, Mater. Charact., 138 (2018) P. 315-324 https://doi.org/10.1016/j.matchar.2017.11.044

5. O.M.Yakovenko, O.S. Roik, V.P. Kazimirov, V.E. Sokol'skii, N.V. Golovataya, G.M. Zelinskaya, T.M. Mika, Structure of the Al-Ge-Fe alloys in the liquid and solid states J. Non-Cryst. Sol., 455 (2017) P.75-82

https://doi.org/10.1016/j.jnoncrysol.2016.10.026

6. О.S. Muratov, O.S. Roik, V.P. Kazimirov, V.K. Nosenko, G.M. Zelinskaya, T.M. Mika, V.E. Sokol’skii, X-ray diffraction studies of the Ni-Si and Al-Ni-Si melts, J. Mol. Liq., 200 (2014) 213-222 https://doi.org/10.1016/j.molliq.2014.10.024

7. O.S. Roik, O.S. Muratov, O.M. Yakovenko, V.P. Kazimirov, N.V. Golovataya, V.E. Sokolskii, X-ray diffraction studies and Reverse Monte Carlo simulations of the liquid binary Fe-Si and Fe-Al alloys, J. Mol. Liq., 197 (2014) P.215-222 https://doi.org/10.1016/j.molliq.2014.05.009

8.       Roik O.S., Kazimirov V.P., Sokolskii V.E., Galushko S.M., Formation of the short-range order in Al-based liquid alloys J. Non-Cryst. Sol., 364 (2013) P.34-39 https://doi.org/10.1016/j.jnoncrysol.2012.12.040

9. O.S. Roik, A.V. Anikeenko, N.N. Medvedev, Investigation of the particular features of the structure factor of liquid Al-based alloys, J. Mol. Liq., 161 (2011) P.78-84 https://doi.org/10.1016/j.molliq.2011.04.010

10. O.S. Roik, O.V. Samsonnikov, V.P. Kazimirov, V.E. Sokolskii, S.M. Galushko, Medium-range order in Al-based liquid binary alloys, J. Mol. Liq., 151 (2010) P.42‑49 https://doi.org/10.1016/j.molliq.2009.11.001

Contacts

PHONE: +38 (044)239-34-17;  

E-MAIL: roikoleksandr1978@gmail.com, oleksandr_roik@knu.ua