Palladium direct methanol fuel cell

Z. Q. Ma, P. Cheng, T. S. Zhao, A Palladium-Alloy Deposited Nafion membrane for Direct Methanol Fuel cells, J. Membr. Sci. 215 (2003) 327-336. 

Palladium electroless deposition was used for coating of Nafion 117 for the application as a membrane in direct methanol fuel cell.59 After the activation of the polymer membrane (Nafion 117) with Pd(II) complexes, reduction was carried out with sodium boro-hydride, NaBH4. Further, autocatalytic deposition of palladium was performed using a commercially available solution. Compared to bare Nafion, the Nafion/Pd composites considerably reduced methanol crossover. This resulted in enhanced cell performance, which was attributed to the existence of the Pd layer at the surface of polymer. 

Ma, Z.Q. Cheng, P. Zhao, T.S. A palladium-alloy deposited Nafion membrane for direct methanol fuel cells. J. Membr. Sci. 2003, 215, 327-336. 

With the experience gathered in the development of direct methanol fuel cells, platinum-ruthenium catalysts were used for the anodic process in the first studies on direct formic acid fiiel cells. Then, it was shown that much better electrical characteristics can be obtained with palladium black as the catalyst. Importantly, with this catalyst, one can work at much lower temperatures. In particular, at a temperature of 30°C power densities of 300 mW/cm were obtained with a voltage of 0.46 V, and about 120 mW/cm with a voltage of 0.7 V. Considering all these special features, it will be very convenient to use formic acid as a reactant in fuel cells of small size, for power supply in portable equipment, ordinarily operated at ambient temperature. 

Brandao L, Rodrigues J, Madeira LM, Mendes A (2010) Methanol crossover reduction by Nafion modification with palladium composite nanoparticles application to direct methanol fuel cells. Int J Hydrogen Energ 35 11561-11567... 

Hosseini J, Bodaghi A (2011) Preparation of palladium nanoparticles-titanium electrodes as a new anode for direct methanol fuel cells. J Solid Slate Electrochem 15 795-800... 

Palladium-alloy materials have been recently introduced as a promising ORR cathode electrocatalyst for replacing Pt [91-98], Pd alloys are considerably less expensive than Pt. Besides, experimental studies indicate that they have high methanol tolerance for direct methanol fuel cells (DMFCs) in which the methanol crossover to the cathode significantly decreases the cell s efficiency [99, 100]. 

Serov AA, Cho S-Y, Han S, Min M, Chai G, Nam KH, Kwak C (2007) Modification of palladium-based catalysts by chalcogenes for direct methanol fuel cells. Elecfrochem Commun 9(8) 2041-2044... 

Soler R, Cacchi S, Fabrizi Get al (2007) Sonogashira Cross-Coupling Using Carbon Aerogel Doped with Palladium Nanoparticles A Recoverable and Reusable Catalyst. Synthesis 19 3068-3072 Du H, Li B, Kang Fet al (2007) Carbon aerogel supported Pt-Ru catalysts for using as the anode of direct methanol fuel cells. Carbon 45 429-435... 

Bae, S.J., Kim, S.-J., Park, J.I., Lee, J.-H., Cho, H., and Park, J.-Y. (2010) Lifetime prediction through accelerated degradation testing of membrane electrode assemblies in direct methanol fuel cells. Int.J. Hydrogen Energy, 35, 9166-9176. Shao, M. (2011) Palladium-based electrocatalysts for hydrogen oxidation and oxygen reduction reactions. J. Power Sources, 196, 2433-2444. 

Abstract The faster kinetics of the alcohol oxidation reaction in alkaline direct alcohol fuel cells (ADAFCs), opening up the possibility of using less expensive metal catalysts, as silver, nickel, and palladium, makes the alkaline direct alcohol fuel cell a potentially low-cost technology compared to acid direct alcohol fuel cell technology, which employs platinum catalysts. In this work an overview of catalysts for ADAFCs, and of testing of ADAFCs, fuelled with methanol, ethanol, and ethylene glycol, formed by these materials, is presented. 

The interest in formic acid oxidation (FAO) rose up in the 1970s with the aim of shedding light on the mechanism of methanol oxidation beyond the commercial interest in direct formic acid oxidation in fuel cells [90]. The FAO in acid solution was extensively investigated on surfaces of platinum [91-100] The FAO on other pure metallic surfaces seems to have been restricted to the palladium surface [98, 101-104]. In the 1980s, the remarkable contribution was done by the studies on the influence of the ad-atom in the activity of the platinum electrode [91—94]. In the 1990s, superficial spectroscopic techniques were employed to describe the electrochemical mechanism on palladium surface [98, 101—103] as well as platinum surface [97, 98, 105]. In the last 10 years, there was a triplication of publications about the FAO, specially driven by the use of nanoparticles. 

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