Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell

Platinum (Pt) is the most commonly adopted electrocatalyst for oxygen reduction reaction in proton exchange membrane fuel cells (PEMFCs) due to its noteworthy features. However, for PEMFCs to have wide practical applications and become commercially viable, the challenging issue of the high catalyst...

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Main Author: Mohamad Yusof, Mohamad Sukri
Format: Thesis
Language:English
Published: 2017
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Online Access:http://eprints.utm.my/id/eprint/77720/1/MohamadSukriMohamadMFChE20171.pdf
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spelling my-utm-ep.777202018-06-29T21:45:06Z Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell 2017-01 Mohamad Yusof, Mohamad Sukri TP Chemical technology Platinum (Pt) is the most commonly adopted electrocatalyst for oxygen reduction reaction in proton exchange membrane fuel cells (PEMFCs) due to its noteworthy features. However, for PEMFCs to have wide practical applications and become commercially viable, the challenging issue of the high catalyst cost, resulting from the exclusive conventional practice of platinum based catalysts should be addressed. Therefore, a study of the palladium (Pd) as a partial substitution to the platinum on carbon (C) has been conducted in high temperature PEMFCs. A series of metal electrocatalyst (Pt/C, Pd/C, and 10-40 wt% Pt-Pd/C) were synthesized via chemical reduction method and their characteristics have been observed by cyclic voltammetry, linear sweep voltammetry, field emission scanning electron microscope and energy dispersion x-ray, Fourier transform infrared spectroscopy, x-ray diffraction and nitrogen-physisorption. Among all, 30 wt% Pt-Pd/C, gave a promising 0.9 Wcm-2 power density at 170 °C. 30 wt% Pt-Pd/C was then nominated to further enhance the catalyst layer. Polybenzimidazole (PBI) was added onto the catalyst layer of 30 wt% Pt-Pd/C in order to inrease the porosity and facilitate the transport of oxygen in the catalyst layer due to their hydrophobic properties. The PBI ratio was varied towards 30 wt% Pt-Pd/C (PBI: 30 wt% Pt-Pd/C; 1:99, 3:97, 5:95 and 9:91). Short-term durability for all catalysts was conducted from 24-96 hr revealed that the impedance curves of 5:95 catalysts showed the slowest performance decay of the membrane electrode assembly (MEA). Hence, this result indicated that the decay of the catalyst could be prevented by appropriate PBI loading as well as increasing the lifetime of the MEA. The 5:95 MEA delivered a peak power density of 1.30 Wcm-2, corresponding to an overall Pt utilization 0.02 mgPt/cm. At 170 °C, the MEA cathodic catalyst utilization was 65 kW/gPt. This is 1.5 times higher than the Pt-utilization efficiency of a reference fuel cell prepared using commercial catalyst layer, which emphasizes the enhancement that was mainly attributing by the Pd substitution and PBI ionomer in the catalyst. All the result indicated in this study strongly motivate the application of combining suitable ratio of PBI binder in an optimum metal loading catalyst. This combination would produce a low resistance MEA in order to compensate an encouraging power density. 2017-01 Thesis http://eprints.utm.my/id/eprint/77720/ http://eprints.utm.my/id/eprint/77720/1/MohamadSukriMohamadMFChE20171.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:105149 masters Universiti Teknologi Malaysia, Faculty of Chemical and Energy Engineering Faculty of Chemical and Energy Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic TP Chemical technology
spellingShingle TP Chemical technology
Mohamad Yusof, Mohamad Sukri
Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
description Platinum (Pt) is the most commonly adopted electrocatalyst for oxygen reduction reaction in proton exchange membrane fuel cells (PEMFCs) due to its noteworthy features. However, for PEMFCs to have wide practical applications and become commercially viable, the challenging issue of the high catalyst cost, resulting from the exclusive conventional practice of platinum based catalysts should be addressed. Therefore, a study of the palladium (Pd) as a partial substitution to the platinum on carbon (C) has been conducted in high temperature PEMFCs. A series of metal electrocatalyst (Pt/C, Pd/C, and 10-40 wt% Pt-Pd/C) were synthesized via chemical reduction method and their characteristics have been observed by cyclic voltammetry, linear sweep voltammetry, field emission scanning electron microscope and energy dispersion x-ray, Fourier transform infrared spectroscopy, x-ray diffraction and nitrogen-physisorption. Among all, 30 wt% Pt-Pd/C, gave a promising 0.9 Wcm-2 power density at 170 °C. 30 wt% Pt-Pd/C was then nominated to further enhance the catalyst layer. Polybenzimidazole (PBI) was added onto the catalyst layer of 30 wt% Pt-Pd/C in order to inrease the porosity and facilitate the transport of oxygen in the catalyst layer due to their hydrophobic properties. The PBI ratio was varied towards 30 wt% Pt-Pd/C (PBI: 30 wt% Pt-Pd/C; 1:99, 3:97, 5:95 and 9:91). Short-term durability for all catalysts was conducted from 24-96 hr revealed that the impedance curves of 5:95 catalysts showed the slowest performance decay of the membrane electrode assembly (MEA). Hence, this result indicated that the decay of the catalyst could be prevented by appropriate PBI loading as well as increasing the lifetime of the MEA. The 5:95 MEA delivered a peak power density of 1.30 Wcm-2, corresponding to an overall Pt utilization 0.02 mgPt/cm. At 170 °C, the MEA cathodic catalyst utilization was 65 kW/gPt. This is 1.5 times higher than the Pt-utilization efficiency of a reference fuel cell prepared using commercial catalyst layer, which emphasizes the enhancement that was mainly attributing by the Pd substitution and PBI ionomer in the catalyst. All the result indicated in this study strongly motivate the application of combining suitable ratio of PBI binder in an optimum metal loading catalyst. This combination would produce a low resistance MEA in order to compensate an encouraging power density.
format Thesis
qualification_level Master's degree
author Mohamad Yusof, Mohamad Sukri
author_facet Mohamad Yusof, Mohamad Sukri
author_sort Mohamad Yusof, Mohamad Sukri
title Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
title_short Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
title_full Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
title_fullStr Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
title_full_unstemmed Carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
title_sort carbon supported palladium-platinum catalyst for oxygen reduction reaction in high temperature proton exchange membrane fuel cell
granting_institution Universiti Teknologi Malaysia, Faculty of Chemical and Energy Engineering
granting_department Faculty of Chemical and Energy Engineering
publishDate 2017
url http://eprints.utm.my/id/eprint/77720/1/MohamadSukriMohamadMFChE20171.pdf
_version_ 1747817815175331840