|
1
|
Ayyubov I, Tálas E, Borbáth I, Pászti Z, Silva C, Szegedi Á, Kuncser A, Yazici MS, Sajó IE, Szabó T, Tompos A. Composites of Titanium-Molybdenum Mixed Oxides and Non-Traditional Carbon Materials: Innovative Supports for Platinum Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1053. [PMID: 38921928 PMCID: PMC11206414 DOI: 10.3390/nano14121053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/14/2024] [Accepted: 06/15/2024] [Indexed: 06/27/2024]
Abstract
TiO2-based mixed oxide-carbon composite support for Pt electrocatalysts provides higher stability and CO tolerance under the working conditions of polymer electrolyte membrane fuel cells compared to traditional carbon supports. Non-traditional carbon materials like graphene nanoplatelets and graphite oxide used as the carbonaceous component of the composite can contribute to its affordability and/or functionality. Ti(1-x)MoxO2-C composites involving these carbon materials were prepared through a sol-gel route; the effect of the extension of the procedure through a solvothermal treatment step was assessed. Both supports and supported Pt catalysts were characterized by physicochemical methods. Electrochemical behavior of the catalysts in terms of stability, activity, and CO tolerance was studied. Solvothermal treatment decreased the fracture of graphite oxide plates and enhanced the formation of a reduced graphene oxide-like structure, resulting in an electrically more conductive and more stable catalyst. In parallel, solvothermal treatment enhanced the growth of mixed oxide crystallites, decreasing the chance of formation of Pt-oxide-carbon triple junctions, resulting in somewhat less CO tolerance. The electrocatalyst containing graphene nanoplatelets, along with good stability, has the highest activity in oxygen reduction reaction compared to the other composite-supported catalysts.
Collapse
Affiliation(s)
- Ilgar Ayyubov
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
- Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Emília Tálas
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
| | - Irina Borbáth
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
| | - Zoltán Pászti
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
| | - Cristina Silva
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
- Department of Physical Chemistry and Materials Science, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
| | - Ágnes Szegedi
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
| | - Andrei Kuncser
- National Institute of Materials Physics, 405A Atomistilor Street, 077125 Magurele, Romania;
| | - M. Suha Yazici
- Energy Institute, Istanbul Technical University, Maslak, 34467 Istanbul, Turkey;
| | - István E. Sajó
- Szentágothai Research Centre, University of Pécs, Ifjúság u. 20., H-7624 Pécs, Hungary;
| | - Tamás Szabó
- Department of Physical Chemistry and Materials Science, University of Szeged, Rerrich Béla tér 1, H-6720 Szeged, Hungary
| | - András Tompos
- Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; (I.A.); (I.B.); (Z.P.); (C.S.); (Á.S.); (A.T.)
| |
Collapse
|
|
2
|
Ayyubov I, Tálas E, Berghian-Grosan C, Románszki L, Borbáth I, Pászti Z, Szegedi Á, Mihály J, Vulcu A, Tompos A. Nitrogen doped carbonaceous materials as platinum free cathode electrocatalysts for oxygen reduction reaction (ORR). REACTION KINETICS MECHANISMS AND CATALYSIS 2022. [DOI: 10.1007/s11144-022-02331-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AbstractComparison of physicochemical properties and electrocatalytic behavior of different N-doped carbonaceous materials as potential catalysts for oxygen reduction reaction (ORR) was attended. Ball-milling of graphite with melamine and solvothermal treatment of graphite oxide, graphene nanoplatelets (GNP) with ammonia were used as preparation methods. Elemental analysis and N2 physisorption measurements revealed the synthesis of N-doped materials with strongly different morphological parameters. Contact angle measurements proved that all three samples had good wettability properties. According to analysis of XRD data and Raman spectra a higher nitrogen concentration corresponded to a smaller size of crystallites of the N-doped carbonaceous material. Surface total N content determined by XPS and bulk N content assessed by elemental analysis were close, indicating homogenous inclusion of N in all samples. Rotating disc electrode tests showed that these N-doped materials weremuch less active in acidic medium than in an alkaline environment. Although the presence of in-plane N species is regarded to be advantageous for the ORR activity, no particular correlation was found in these systems with any type of N species. According to Koutecky–Levich analysis, both the N-containing carbonaceous materials and the reference Pt/C catalyst displayed a typical one-step, four-electron ORR route. Both ball-milled sample with high N-content but with low SSA and solvothermally synthesized N-GNP with high SSA but low N content showed significant ORR activity. It could be concluded that beside the total N content other parameters such as SSA, pore structure, structural defects, wettability were also essential for achieving high ORR activity.
Collapse
|
|
3
|
Role of the Potential Range during Stress Testing of Platinum-Containing Electrocatalysts at Elevated Temperature. Catalysts 2022. [DOI: 10.3390/catal12101179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The durability of low temperature proton exchange membrane fuel cell (PEMFC) catalysts crucially affects their lifetime. The choice of carbon support is important in terms of increasing the stability of catalysts. In this research, Pt/C samples were obtained using the polyol synthesis method on two types of carbon supports: the standard support, Vulcan XC-72, and carbon support with a high degree of graphitization, ECS-002402. One method for assessing structural characteristics is through transmission electron microscopy (TEM), according to which materials G1 and G2 showed an average nanoparticle size of 3.7 and 4.2 nm, respectively. On all catalysts, the oxygen reduction reaction proceeded according to the four electron mechanism. Durability was assessed by changes in ESA and activity in the ORR after 1000 cycles, with changes in the upper potential values: 0.7; 1.0; 1.2; and 1.4 V. After accelerated stress testing, the G1 material showed the greatest residual activity at a potential of 1.4 V (165 A/g (Pt). Based on the results of comparing various ADT protocols, the optimal mode of 0.4 and 1.4 V was chosen, and should be used for further studies comparing the durability of Pt/C catalysts.
Collapse
|