98
(Fig. 7.15). O 2 reduction on a Pt monolayer on Pd(111) generates some H 2 O 2 , which
is detected by oxidation on the ring kept at 1.27 V, Fig. 7.14a. The key parameter
which characterizes a given ring-disk geometry is the collection efficiency factor.
The collection efficiency is the fraction of the material from the disk which lows
past the ring electrode. Typically, N is of the order of 20% or more. While N can be
calculated for a given geometry, it is usually determined experimentally by using a
simple electron-transfer reaction.
References
1. S.R. Brankovic, J.X. Wang, R.R. Adžić, Pt submonolayers on Ru nanoparticles: A novel low
Pt loading, high CO tolerance fuel cell Electrocatalyst. Electrochem. Solid-State Lett. 4(12),
A217–A220 (2001)
2. J. Zhang, Y. Mo, M.B. Vukmirovic, R. Klie, K. Sasaki, R.R. Adzic, Platinum monolayer electrocatalysts for O2 reduction: Pt monolayer on Pd (111) and on carbon-supported Pd nanoparticles. J. Phys. Chem. B 108(30), 10955–10964 (2004)
3. J. Zhang, M.B. Vukmirovic, K. Sasaki, A. Nilekar, M. Mavrikakis, R.R. Adzic, Mixed-metal
Pt monolayer electrocatalysts for enhanced oxygen reduction kinetics. J. Am. Chem. Soc.
127(36), 12480–12481 (2005)
4. S.R. Brankovic, J.X. Wang, R.R. Adzic, Metal monolayer deposition by replacement of metal
adlayers on electrode surfaces. Surf. Sci. 474, L173–L179 (2001)
5. K. Sasaki, H. Naohara, Y. Cai, Y.M. Choi, P. Liu, M.B. Vukmirovic, J.X. Wang, R.R. Adzic,
Core-protected platinum monolayer Shell high-stability electrocatalysts for fuel-cell cathodes.
Angew. Chem. Int. Ed. 49, 8602 (2010)
6. M.B. Vukmirovic, S.T. Bliznakov, K. Sasaki, J.X. Wang, R.R. Adzic, Electrodepostition of
metals in catalyst synthesis: The case of platinum monolayer electrocatalysis. Elecrochem.
Soc. Interface 20(2), 33–40.26 (2011)
7. F.H.B. Lima, J. Zhang, M.H. Shao, K. Sasaki, M.B. Vukmirovic, A. Ticianelli, R.R. Adzic,
Catalytic activity – d-band center correlation for the O2 reduction reaction on platinum in
alkaline solutions. J. Phys. Chem. C 111, 404–410 (2007)
Fig. 7.15 Schematics of
rotating ring-disk electrode
7 Platinum Monolayer Electrocatalysts
(Fig. 7.15). O 2 reduction on a Pt monolayer on Pd(111) generates some H 2 O 2 , which
is detected by oxidation on the ring kept at 1.27 V, Fig. 7.14a. The key parameter
which characterizes a given ring-disk geometry is the collection efficiency factor.
The collection efficiency is the fraction of the material from the disk which lows
past the ring electrode. Typically, N is of the order of 20% or more. While N can be
calculated for a given geometry, it is usually determined experimentally by using a
simple electron-transfer reaction.
References
1. S.R. Brankovic, J.X. Wang, R.R. Adžić, Pt submonolayers on Ru nanoparticles: A novel low
Pt loading, high CO tolerance fuel cell Electrocatalyst. Electrochem. Solid-State Lett. 4(12),
A217–A220 (2001)
2. J. Zhang, Y. Mo, M.B. Vukmirovic, R. Klie, K. Sasaki, R.R. Adzic, Platinum monolayer electrocatalysts for O2 reduction: Pt monolayer on Pd (111) and on carbon-supported Pd nanoparticles. J. Phys. Chem. B 108(30), 10955–10964 (2004)
3. J. Zhang, M.B. Vukmirovic, K. Sasaki, A. Nilekar, M. Mavrikakis, R.R. Adzic, Mixed-metal
Pt monolayer electrocatalysts for enhanced oxygen reduction kinetics. J. Am. Chem. Soc.
127(36), 12480–12481 (2005)
4. S.R. Brankovic, J.X. Wang, R.R. Adzic, Metal monolayer deposition by replacement of metal
adlayers on electrode surfaces. Surf. Sci. 474, L173–L179 (2001)
5. K. Sasaki, H. Naohara, Y. Cai, Y.M. Choi, P. Liu, M.B. Vukmirovic, J.X. Wang, R.R. Adzic,
Core-protected platinum monolayer Shell high-stability electrocatalysts for fuel-cell cathodes.
Angew. Chem. Int. Ed. 49, 8602 (2010)
6. M.B. Vukmirovic, S.T. Bliznakov, K. Sasaki, J.X. Wang, R.R. Adzic, Electrodepostition of
metals in catalyst synthesis: The case of platinum monolayer electrocatalysis. Elecrochem.
Soc. Interface 20(2), 33–40.26 (2011)
7. F.H.B. Lima, J. Zhang, M.H. Shao, K. Sasaki, M.B. Vukmirovic, A. Ticianelli, R.R. Adzic,
Catalytic activity – d-band center correlation for the O2 reduction reaction on platinum in
alkaline solutions. J. Phys. Chem. C 111, 404–410 (2007)
Fig. 7.15 Schematics of
rotating ring-disk electrode
7 Platinum Monolayer Electrocatalysts