Improved Methanol Oxidation Activity Through Oxidation-Induced Phase Separation of PtRu Electrocatalysts

2000 ◽  
Vol 6 (S2) ◽  
pp. 24-25
Author(s):  
R.M. Stroud ◽  
J.W. Long ◽  
K.E. Swider ◽  
D.R. Rolison

Direct methanol fuel cells (DMFCs) offer a simpler, safer technology for point-of-use power sources compared to other hydrogen fuel cells, by avoiding the need to store hydrogen fuel or to carry out the reformation of hydrocarbons. The direct methanol oxidation electrocatalyst of choice is a nanoscale black consisting of a 50:50 atom % mixture of Pt and Ru. It has recently become known that these presumed bimetallic alloys in fact contain an array of metal, oxide and hydrous phases, which are easily misidentified in routine x-ray diffraction measurements due to particle size-broadening and poor crystallinity. By combining transmission electron microscopy, electrochemistry and thermogravimetric studies, we demonstrate here that the route to improved catalytic activity is not by phase purification of the bimetallic alloys, but instead phase engineering of hydrous ruthenium oxide and Pt mixtures.

2013 ◽  
Vol 11 (3) ◽  
Author(s):  
Brenda L. García-Díaz ◽  
Héctor R. Colón-Mercado ◽  
Kevin Herrington ◽  
Elise B. Fox

High temperature direct methanol fuel cells (DMFCs) using polybenzimidazole (PBI) membranes could improve the energy density of portable power sources. This study examines the polarization of vapor phase PBI DMFCs constructed with commercial membranes manufactured by a sol-gel method. The polarization of the high temperature DMFCs is compared to similar low temperature membrane electrode assemblies (MEAs) using Nafion® membranes. The results showed that the cathode of the PBI DMFC had higher kinetic losses that are likely due to phosphate poisoning of the Pt electrocatalyst. At the tested conditions, the membrane conductivity of the PBI MEAs was comparable to the Nafion® MEA even with no humidification. Higher cell temperatures significantly improved PBI DMFC performance for Pt electrocatalyst electrodes. In full cell tests, the PBI DMFC MEAs had higher performance than Nafion® MEAs with similar catalyst loadings. The Pt and PtRu catalysts were tested for methanol oxidation and oxygen reduction activity by a rotating disk electrode (RDE) under 0.5 M H2SO4 and 0.5 M H3PO4. The combination of the polarization and RDE results for the PBI and Nafion® DMFCs suggest that Pt is a more active electrocatalyst for methanol oxidation in PBI than in Nafion®.


Nanoscale ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 4719-4728 ◽  
Author(s):  
Yunshan Zheng ◽  
Yan Zhai ◽  
Maomao Tu ◽  
Xinhua Huang ◽  
Mingcong Shu ◽  
...  

The design and fabrication of economically viable anode catalysts for the methanol oxidation reaction (MOR) have been challenging issues in direct methanol fuel cells (DMFCs) over the decades.


2016 ◽  
Vol 4 (47) ◽  
pp. 18607-18613 ◽  
Author(s):  
Jinfa Chang ◽  
Ligang Feng ◽  
Kun Jiang ◽  
Huaiguo Xue ◽  
Wen-Bin Cai ◽  
...  

A novel Pt–CoP/C electrocatalyst was developed for direct methanol fuel cells. This catalyst showed superior power density to commercial Pt/C and PtRu/C catalysts. In situ ATR-SEIRAS technology revealed that the presence of CoP in the Pt-based catalyst can promote the methanol oxidation to final CO2 products.


2014 ◽  
Vol 93 ◽  
pp. 61-64
Author(s):  
A.S. Aricò

Direct Methanol Fuel Cells (DMFCs) have been postulated as suitable systems for power generation in the fields of portable power sources, remote and micro-distributed energy generation, and auxiliary power units (APU). The main objective of the DURAMET project ((http://www.duramet.eu) is to develop cost-effective components for DMFCs with enhanced activity and stability in order to reduce stack costs and improve performance and durability. The project concerns with the development of DMFC components for application in auxiliary power units and portable systems.


2010 ◽  
Vol 27 (3) ◽  
pp. 802-806 ◽  
Author(s):  
Dae Kyu Kang ◽  
Chang Soo Noh ◽  
Sang Tae Park ◽  
Jung Min Sohn ◽  
Seung Kon Kim ◽  
...  

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