9 / 33
Page 92
conferenceseries
.com
Volume 7
Innovative Energy & Research
ISSN: 2576-1463
Advanced Energy Materials 2018
August 13-14, 2018
August 13-14, 2018 | Dublin, Ireland
20
th
International Conference on
Advanced Energy Materials and Research
Support less Ag-Rh bimetallic nanostructures as efficient cathodic electro catalyst for di oxygen
reduction in alkaline fuel cells
Il Shik Moon
1
, B Narayanamoorthy
2
and
S Balaji
1, 2
1
Sunchon National University, South Korea
2
Sri Chandrasekharendra Saraswathi Viswa Mahavidyalaya, India
T
he non-platinum d-block elements can be employed as ORR electrocatalysts due to their catalytic activity which help us to
reduce or replace the usage of expensive precious metal catalysts in alkaline fuel cells. A number of cathode electrocatalysts
are available such as non-platinum metals (Ag, Au, Pd, etc.) and the non-noble metals (Fe, Co, Ni, Cu, etc.) but they either
suffer from low activity or poor stability. Among the noble metal electrocatalysts, Ag is relatively inexpensive (ca. 1% the price
of Pt), abundant and reasonably active catalyst with moderate stability and therefore, Ag is an attractive choice for enhancing
the kinetics of oxygen reduction in alkaline medium. The redox potential of Rh3+ to Rh is 0.76 V whereas the redox potential of
Ag+ to Ag is 0.8 V. The electrochemical activity of pure Rh is very poor but it could provide the additional stability when mixed
with other catalyst materials. Hence, formation of Ag-Rh nanostructures may provide to be useful approach for improving the
stability in a cost effective way. Silver-rhodium (Ag-Rh) nanostructured electro catalysts were synthesized by one step chemical
reduction method and used to catalyze the oxygen reduction reaction (ORR) in an alkaline medium. The crystalline nature
was ascertained by x-ray diffraction (XRD), elemental composition was estimated by energy dispersive spectroscopy and
morphology was confirmed high resolution transmission electron microscope. The electrochemical properties were studied
by cyclic and linear scan voltammetry techniques under hydrodynamic conditions. The supportless Ag-Rh catalyst exhibited a
good catalytic activity for ORR and the quantified values in terms of higher mass and intrinsic activities were determined to be
951.7 mA/mg and 1.45 mA/cm
2
respectively. Accelerated durability test revealed that the catalyst could withstand nearly 7000
potential cycles with 5% increment in limited current density while retaining nearly 70% of its initial electrochemically active
surface area. This study indicates the superior activity and stability of Ag-Rh (compared to Ag-Rh/VC) undoubtedly places it
as one among the promising electrocatalysts for ORR in alkaline medium.
Fig. 1
XRD patterns of supportless and VC supported Ag-Rh catalyst & SEM image of Ag-Rh catalyst.
Recent Publications:
1. Slanac D A, Hardin W G, Johnston K P, Stevenson K J (2012) Atomic ensemble and electronic effects in Ag-rich Ag-
Pd nanoalloy catalysts for oxygen reduction in alkaline media, Journal of American Chemical Society 134:9812-9819.
2. Bin F, Jin L, Peter N, Rameshwori L, Derrick M, Bridgid W, Xiang H and Chuan-Jian Z (2009) Nanostructured PtVFe
catalysts: Electrocatalytic performance in proton exchange membrane fuel cells, Electrochemistry Communications
11:1139-1141.
3. Nguyen S T, Law HM, Nguyen H T, Kristian N, Wang S, Chan S H, Wang X (2009) Enhancement effect of Ag for Pd/C
towards the ethanol electro-oxidation in alkaline media, Applied Catalysis B, 91:507-515.
4. Narayanamoorthy B, Balaji S, Sita C, Pasupathi S, Eswaramoorthy M, Il-Shik Moon (2016) Enhanced Intrinsic Activity
and Stability of Au-Rh Bimetallic Nanostructures as a Supportless Cathode Electrocatalyst for Oxygen Reduction in
Alkaline Fuel Cells, ACS Sustainable Chemistry and Engineering, 4:6480-6490.
Il Shik Moon et al., Innov Ener Res 2018, Volume 7
DOI: 10.4172/2576-1463-C1-003