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Electrochemical analysis of the porphyrazine-induced enhancement of ORR activity of Pt catalysts for the development of porphyrazine-adsorbed Pt catalysts
- Source :
- Journal of Electroanalytical Chemistry. 848:113321
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- The enhancement of the oxygen reduction reaction (ORR) activity of Pt catalysts by porphyrazines (tetraazaporphyrin and phthalocyanine) is analyzed electrochemically. While tetra(t-butyl)tetraazaporphyrin significantly enhances the ORR activity, the enhancement by dilithium phthalocyanine is limited; this molecule increases the ORR at high potentials but decreases it at low potentials. The cyclic voltammograms (CVs) under an Ar atmosphere and a Tafel analysis reveal that the phthalocyanine promotes the ORR by destabilization of OHad, an intermediate of the ORR, at high potentials. However, this positive effect of the phthalocyanine is counteracted by its inhibitory effects at low potentials. Thus, the tetra(t-butyl)tetraazaporphyrin, which does not have a significant inhibitory effect, would be a better enhancer. The method for preparing tetra(t-butyl)tetraazaporphyrin-adsorbed Pt catalysts was investigated. This molecule is not only mainly adsorbed on a carbon black support, but also adsorbed on the surface of Pt nanoparticles. Tetra(t-butyl)tetraazaporphyrin-adsorbed carbon-supported Pt nanoparticles are prepared by an equilibrium adsorption method and an evaporation-to-dryness method. The optimized preparation method is discussed. Using the evaporation-to-dryness method, we also examined the effects of several porphyrins on the ORR of Pt catalysts.
- Subjects :
- Tafel equation
biology
General Chemical Engineering
Inorganic chemistry
02 engineering and technology
Porphyrazine
Carbon black
010402 general chemistry
021001 nanoscience & nanotechnology
Electrochemistry
biology.organism_classification
01 natural sciences
0104 chemical sciences
Analytical Chemistry
Catalysis
chemistry.chemical_compound
Adsorption
chemistry
Phthalocyanine
Tetra
0210 nano-technology
Subjects
Details
- ISSN :
- 15726657
- Volume :
- 848
- Database :
- OpenAIRE
- Journal :
- Journal of Electroanalytical Chemistry
- Accession number :
- edsair.doi...........c1a9fdc60dbfb77d8fb8db110b766c3e