Elsheikh, A. and McGregor, J. orcid.org/0000-0001-6813-306X (2023) Unexpected negative performance of PdRhNi electrocatalysts toward ethanol oxidation reaction. Micromachines, 14 (5). 957. ISSN 2072-666X
Abstract
Direct ethanol fuel cells (DEFCs) need newly designed novel affordable catalysts for commercialization. Additionally, unlike bimetallic systems, trimetallic catalytic systems are not extensively investigated in terms of their catalytic potential toward redox reactions in fuel cells. Furthermore, the Rh potential to break the ethanol rigid C-C bond at low applied potentials, and therefore enhance the DEFC efficiency and CO2 yield, is controversial amongst researchers. In this work, two PdRhNi/C, Pd/C, Rh/C and Ni/C electrocatalysts are synthesized via a one-step impregnation process at ambient pressure and temperature. The catalysts are then applied for ethanol electrooxidation reaction (EOR). Electrochemical evaluation is performed using cyclic voltammetry (CV) and chronoamperometry (CA). Physiochemical characterization is pursued using X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). Unlike Pd/C, the prepared Rh/C and Ni/C do not show any activity for (EOR). The followed protocol produces alloyed dispersed PdRhNi nanoparticles of 3 nm in size. However, the PdRhNi/C samples underperform the monometallic Pd/C, even though the Ni or Rh individual addition to it enhances its activity, as reported in the literature herein. The exact reasons for the low PdRhNi performance are not fully understood. However, a reasonable reference can be given about the lower Pd surface coverage on both PdRhNi samples according to the XPS and EDX results. Furthermore, adding both Rh and Ni to Pd exercises compressive strain on the Pd lattice, noted by the PdRhNi XRD peak shift to higher angles.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
Keywords: | ethanol oxidation reaction; trimetallic nanoparticles; Rh effect; surface metal segregation |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Chemical and Biological Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 03 May 2023 09:36 |
Last Modified: | 03 May 2023 09:36 |
Status: | Published |
Publisher: | MDPI AG |
Refereed: | Yes |
Identification Number: | 10.3390/mi14050957 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:198700 |