Electrocatalyst preparation

GustavssonM, Fredriksson H, Kasemo B, Jusys Z, Jun C, Behm RJ. 2004. Nanostructured platinum-on-carbon model electrocatalysts prepared by colloidal lithography. J Electroanal Chem 568 371-377. 

Santhosh, P., A. Gopalan, and K.-P. Lee, Gold nanoparticles dispersed polyaniline grafted muttiwall carbon nanotubes as newer electrocatalysts Preparation and performances for methanol oxidation. Journal of Catalysis, 2006. 238(1) p. 177-185. 

M. Morita, Y. Iwanaga, and Y. Matsuda, Anodic-oxidation of methanol at a gold-modified platinum electrocatalyst prepared by RE-sputtering on a glassy-carbon support, Electrichim. Acta 36, 947-951 (1991). 

Bonakdarpour, A., Fleischauer, M. D., Brett, M. J., and Dahn, J. R. Columnar support structures for oxygen reduction electrocatalysts prepared by glancing angle deposition. Applied Catalysis A General 2008 349 110-115. 

Ramaswamy N, Arruda TM, Wen W, Hakim N, Saha M, Gulla A, Mukcrjee S (2009) Enhanced activity and interfacial durability study of ultra low Pt based electrocatalysts prepared by ion beam assisted deposition (IBAD) method. Electrochim Acta 54 6756-6766 Wu J, Yuan XZ, Martin JJ, Wang H, Zhang J, Shen J, Wu S, Merida W (2008) A review of PEM fuel cell durability degradation mechanisms and mitigation strategies. J Power Sources 184 104-119... 

Figure 4. Ohmic Corrected Tafel Plots for Oxygen Reduction on Pt and Pt Alloy Electrocatalysts Prepared at Northeastern (note that PtCr/C is a system being considered only for ORR fundamentals it will not be under consideration for down-selection)...

Characterize Pt/Ru electrocatalysts prepared by a new method involving a spontaneous deposition of Pt on Ru nanoparticles. 

PtSn/C electrocatalysts prepared by different methods for direct ethanol fuel cell... 

Recently, Lamy and co-workers [4,5] described that PtSn/C electrocatalysts were more active than PtRu/C electrocatalysts for ethanol oxidation. For electrocatalysts prepared by co-impregnation-H2 reduction and Bonneman methods, they found that the optimum tin composition was in the range of 10-20 at.%. In these conditions, the electrode activity was enhanced and the CO-intermediates coming from ethanol dissociative chemisorption were reduced. Xin and co-workers [6-9] prepared PtRu/C and PtSn/C electrocatalysts by a polyol method and tested for ethanol oxidation. It was observed that the addition of some elements, like W, could improve the PtRu/C electrocatalyst activity. However, the activities of the PtRu/C electrocatalysts were inferior to those of PtSn/C electrocatalysts. It was also found that PtSn/C electrocatalysts with Pt Sn atomic ratios of 60 40 and 50 50 were more active than electrocatalysts with 75 25 and 80 20 atomic ratios. Thus, it seems that the performance of PtSn/C electrocatalysts depends greatly on their preparation procedure. 

The measured Pt Sn atomic ratios of the obtained electrocatalysts prepared by ARP and BH methods were similar to the nominal atomic ratios used in the preparations (Table 1). 

For PtSn/C electrocatalysts prepared by ARP method, the onset potential observed for PtSn/C electrocatalyst with a Pt Sn atomic ratio of 50 50 ( 0.25V)... 

Pt/C and PtiRui/C electrocatalysts prepared by alcohol reduction process... 

For polymer electrolyte membrane fuel cell (PEMFC) applications, platinum and platinum-based alloy materials have been the most extensively investigated as catalysts for the electrocatalytic reduction of oxygen. A number of factors can influence the performance of Pt-based cathodic electrocatalysts in fuel cell applications, including (i) the method of Pt/C electrocatalyst preparation, (ii) R particle size, (iii) activation process, (iv) wetting of electrode structure, (v) PTFE content in the electrode, and the (vi) surface properties of the carbon support, among others. ... 

Fig. 1.34 Oxygen reduction half-cell studies Evaluation of electrocatalyst preparation. Comparison of sputtered R electrode with Etek electrode (0.5 mg/cm R loading). 1.0 M sulfuric acid under 10 psig Oxygen Pressure (2.0 L/min. flow rate) at 25 °C.

Case Study 2 Carbon (Vulcan XC72) Supported Bimetalhc Electrocatalysts. Preparation by the borate method of Pt-Cu colloidal catalysts having structural variations and comparative study of their electrochemical performance. 

P. Santhosh, A. Gopalan, K. Lee, Gold Nanoparticles Dispersed Polyaniline Grafted Multiwall Carbon Nanotubes as Newer Electrocatalysts Preparation and Performances for Methanol Oxidation. /. Catal. 2006,238, 177-185. 

De Souza REB, Elausino AEA, Rascio DC, Oliveira RTS, Teixeira Neto E, Calegaro ML, Santos MC (2009) Ethanol oxidation reaction on PtCe02/C electrocatalysts prepared by the polymeric precursor method. Appl Catal B Environ 91 516-523... 

In 2001, Tarasevich and his collaborators reported a comparison between electrocatalysts for oxygen reduction prepared using a disperse synthetic diamond powder promoted with CoTMPP and its pyropolymers . Two types of diamond powders with specific area of 5.8 and 170 m /g were used as catalyst supports and the activity of the catalysts obtained with the diamond supports was compared to that obtained with the same CoTMPP precursor loaded on acetylene black. In all cases, the loading was one monolayer of CoTMPP. These authors found a much lower activity for the electrocatalysts prepared on synthetic diamonds than for that catalyst prepared on acetylene black. The kinetic mechanisms of ORR was, however, the same for both supports. 

Antolini E, Salgado JRC, Gonzalez ER. Oxygen reduction on a Pt7oNi3o/C electrocatalyst prepared by the borohydride method in IT2SO4/CH3OH solutions. / Power Sources 2006 155(2) 161-6. 

Figure 14. Structural models estimated from EXAFS analysis for the indicated electrocatalysts prepared as deseribed in Ref 57. The PtRu Mix catalyst was prepared by mechanically mixing Pt/C and Ru/C powder, with some atoms of the other element thereby being deposited on each cluster surface.

Oliveira Neto A, Franco EG, Arico E, Linardi M, Gonzalez ER (2003) Electro-oxidation of methanol and ethanol on Pt-Ru/C and Pt-Ru-Mo/C electrocatalysts prepared by Bdnnemann s method. J Eur Ceram Soc 23 2987-2992... 

Neto AO, Dias RR, Tusi MM, Linardi M, Spinace EV (2007) Electro-oxidation of methanol and ethanol using PtRu/C, PtSn/C and PtSnRu/C electrocatalysts prepared by an alcohol-reduction process. J Power Sources 166 87-91... 

Wang RF, Liao SJ, Fu ZY, Ji S (2008) Platinum free ternary electrocatalysts prepared via organic colloidal method for oxygen reduction. Electrochem Commun 10(4) 523-526... 

Raghuveer V, Ferreira PJ, Manthiram A (2006) Comparison of Pd-Co-Au electrocatalysts prepared by conventional borohydride and microemulsion methods for oxygen reduction in fuel cells. Electrochem Commun 8(5) 807-814... 

Price SWT, Speed JD, Kannan P, Russell AE (2011) Exploring the first steps in core-shell electrocatalyst preparation in situ characterisation of the underpotential deposition of Cu on supported Au nanoparticles. J Am Chem Soc 133 19448-19458... 

Electrocatalytic Reduction of Oxygen. Oxygen reduction reaction (ORR) occurs on the cathode side of low temperature fuel cells and heavily loaded Pt/C is the most common electrocatalyst. Replacement of ORR catalysts with less expensive materials would have higher technical impact than for anode catalysts. Transition metals loaded carbides and carbide-metal codeposited carbon have been investigated for ORR application. For example, 40 wt% Pt/WC electrocatalyst prepared with RDE electrode showed a cathodic current (-5 x 10 A) similar to that of 40 wt% Pt/C with 0.5 M H2SO4, 100 mv/s and 2000 rpm (160). Also, 40 wt% Pt/WC exhibited electrochemical stability after 100 cycles of cyclic voltammetry from 0 to 1.4 V (vs RHE), whereas the cathodic current of 40 wt% Pt/C disappeared after 100 cycles. 

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