Abstract
Fuel cell technology is a promising green alternative to fossil fuels for transport and other applications. Miniature fuel cells that use biomass derived hydrogen have been attracting special attention recently. It has been shown that nanoscale Pt structures, such as ultrathin layers and Pt- M nano-alloys, often have chemical and physical properties that are superior to those of bulk Pt due to the combination of electronic and geometric effects. Previous studies have reported that the Pt-Pd system is potentially a high-performance electrocatalytic system with high CO tolerance.Surface Limited Redox Replacement (SLRR) is one of the most successful approaches used to produce Pt and Pt bimetallic catalysts with precise control of their atomic structure. This method is based on the replacement of an underpotentially deposited (UPD) layer of a less noble metal by a more noble metal (such as Pt and Pd) through an irreversible surface-controlled redox reaction.
In this work, epitaxial alloy thin films up to 10 R were grown from a sulphate electrolyte in a one-cell configuration using Cu UPD monolayers as sacrificial layers. The alloy composition and structure were controlled by the ratio of Pt and Pd complex concentrations in the electrolyte. Alloy structure and composition were examined by a combination of electrochemical and surface science methods. The activity and stability of alloys were also examined during formic acid oxidation. In addition, the dissolution of PtxPd100-x alloy was confirmed by AFM.
| Date of Award | 6 Dec 2022 |
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| Original language | English |
| Awarding Institution |
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| Supervisor | Natasa Vasiljevic (Supervisor) & Walther Schwarzacher (Supervisor) |