Electrodeposition of Pd-Based Binary Catalysts on Carbon Paper Via Surface-Limited Redox-Replacement Reactions for Oxygen Reduction Reaction

Direct alcohol fuel cells (DAFCs) continue to extensive attention as potential power sources for portable and stationary applications [1]. The oxygen reduction reaction (ORR) involving the four electron transfer remains a challenge for DAFCs due to its slow kinetics. Research activities worldwide are focussed on improving the performance of ORR catalysts, reducing the amount of Pt required in DAFCs and in addition, developing catalysts tolerant to alcohol (alcohol crossover). Pd has attracted enormous attention as it is more abundant and also cheaper than Pt [2-5].

In this presentation, Electrochemical Atomic Layer Deposition (ECALD) was used in the preparation of binary ORR catalysts. The binary nanoclusters were synthesised via surface-limited redox-replacement reaction (SLR³) with Cu as a sacrificial metal. Co-deposition of the two metals on carbon paper was also performed. ECALD is the appropriate fabrication methodology because the resultant catalysts showed good dispersion of the nanoclusters on the carbon paper. This will reduce the amount of Pt and increase the utilization of the catalyst. The prepared binary nanoclusters were evaluated for the ORR.

References:

 

1. F. Barbir, PEM Fuel Cells: Theory and Practice, Elsevier Academic Press, 2005, Oxford: p. 1-16
2. A. Kiani, E.N. Fard, Fabrication of palladium coated nanoporous gold film electrode via underpotential deposition and spontaneous metal replacement: A low palladium loading electrode with electrocatalytic activity, Electrochim. Acta. 54 (2009) 7254-7259.
3. T.S. Mkwizu, M.K. Mathe, I. Cukrowski, Electrodeposition of Multilayered Bimetallic Nanoclusters of Ruthenium and Platinum via Surface-Limited Redox− Replacement Reactions for Electrocatalytic Applications, Langmuir. 26 (2009) 570-580.
4. L.B. Sheridan, D.K. Gebregziabiher, J.L. Stickney, D.B. Robinson, Formation of Palladium nanofilms using Electrochemical Atomic Layer Deposition (E-ALD) with Chloride complexation, Langmuir 29 (2013) 1592

5. R.M. Modibedi, M.K. Mathe, R.G. Motsoeneng, L.E. Khotseng, K.I. Ozoemena, E.K. Louw, Electro-deposition of Pd on Carbon paper and Ni foam via surface limited redox-replacement reaction for oxygen reduction reaction, Electrochimica Acta (2013), accepted for publication