Razumevanje potenciala visokoentropijskih oksidov za elektrokatalizo
Oznaka in naziv projekta
N2-0390 Razumevanje potenciala visokoentropijskih oksidov za elektrokatalizo
N2-0390 Understanding the Potential of High-Entropy Oxides for Electrocatalysis
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Projektna skupina
Vodja projekta: dr. Alcantara Marinho Belisa
Sodelujoče raziskovalne organizacije: Povezava na SICRIS /
Sestava projektne skupine: Povezava na SICRIS
55496 - Belisa Alcantara Marinho - https://cris.cobiss.net/ecris/si/sl/researcher/52219
58380 - Lara Einfalt - https://cris.cobiss.net/ecris/si/sl/researcher/55552
55788 - Barbara Ljubec Božiček - https://cris.cobiss.net/ecris/si/sl/researcher/52606
Vsebinski opis projekta
Vsebinski opis projekta
UPHEO4CAT will explore the main hypothesis is that an explicit correlation between HEOs’ elemental composition, single crystal formation and catalytic activity exists and is critical to our understanding and for guiding future research. This knowledge is fundamental to precisely control the compositions and structures, and to understand the catalytic mechanisms behind HEO’s multiple active sites. UPHEO4CAT aims to research these fundamental aspects by exploring the following research conjectures:
• A simple method to obtain HEO is beneficial for both scientific experiments and future large-scale applications. To be used in electrodes, HEOs should be strongly adhered in the support. Thus, anodic oxidation of HEAs seems to be an efficient route to obtain HEO thin films (my research group already reported the feasibility of this method). UPHEO4CAT proposes that, to a certain extent, any HEA can be converted into a stable single-phase HEO, and this strategy can be used to understand the elemental composition-single phase formation correlation in HEOs.
• The combination of mixed active sites present in HEOs are more efficient than tuned specific active sites. Various parameters, such as the degree of d-band filling, the spin state, charge difference, electronegativity, oxygen vacancies, lattice distortion and crystal orientation, can be systematically regulated and used to explain the structure-catalytic activity correlation. The electrochemical characterization of the produced HEOs will help to explore the catalytic activity and serve as the basis for future correlation with the presence of certain active sites in these materials
Osnovni podatki sofinanciranja so dostopni na spletni strani SICRIS.
Faze projekta in opis njihove realizacije
Phase 1 - elemental composition-single phase formation (months 1 – 16):
Initially, CoFeNiMnCr alloy will be submitted to anodization (AO) + annealing (AN) treatment, as well as other similar systems, including CoFeNi, CoFeNiMn, CoFeNiCr, CoFeNiCrCo, CoFeNiMnCu, CoFeNiCuTi. The AO process will be performed in a custom-built laboratory, each electrochemical cell willbe equipped with: i) the counter electrode - platinum grid; and ii) the working electrode - HEA samples (Ø4 – Ø20 mm); iii) the reference electrode -reversible hydrogen electrode.
- The electrolyte type and concentration, applied potential and anodization time will be evaluated. After anodization, the produced nanofilm will be amorphous, and heattreatment will be optimised and used to crystallise the material in an O2 atmosphere. Annealing temperatures from 200 to 1000°C will be evaluated. The obtained materials will be characterized in terms of morphology, structure, surface, chemical composition, atomic coordination, and defects. By the end of this phase, qualitative (morphology, single phase formation, crystallinity, oxidation states, etc.) and quantitative (atomic ratio of elements in the oxide film, thin film thickness, etc.) results will be correlated and used to resolve two important questions: to which extent may previously obtained single-phase HEAs be converted into stable single-phase HEOs,and what is the correlation between certain elemental compositions and the formation of nanostructured HEO thin films on HEAs?
Phase 2 - structure-catalytic activity (months 10 – 24):
The ambition in this step is to understand how the elemental composition and nanostructured single-phase HEOs are integral to electrocatalytic activity. To achieve this goal, the electrochemical characterization of the materials produced in Phase 1 will be performed to follow the OER reaction and determine the active surface area, onset potential, overpotential, Tafel slope, charge-transfer resistance of the materials and short-term stability. The results obtained in this step will be used to understand how the structural and morphological characteristics of the obtained materials are correlated to the activity for OER.