Res. Chem. Intermed.
, Vol. 34, Nos 8–9, pp. 853–861 (2008)
Koninklijke Brill NV, Leiden, 2008.
Also available online - www.brill.nl/rci
Preparation of Pt/C catalyst using alcohol reduction and
a polyol process in the presence of urea for oxygen
HYUNG-SUK OH, JONG-GIL OH, YOUN-GI HONG,
RAJ KISHORE SHARMA, YONG-GUN SHUL and HANSUNG KIM
Department of Chemical Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemun-gu,
Seoul 120-749, South Korea
Received 6 July 2007; accepted 29 August 2007
Abstract—The effect of urea hydrolysis was studied on the preparation and properties of Pt/C
catalyst. The hydrolysis of urea provided hydroxyl ions in a controlled manner that prevented the
localized pH change in the solution and only surface precipitation is resulted in a particle growth.
From rotating ring disk electrode (RRDE) experiments, the Pt/C prepared in the presence of urea
showed better exchange current density toward the oxygen reduction reaction. The rate of H
formation was reduced when urea was used in the alcohol reduction process and it was further
decreased in the Pt/C catalyst prepared by the polyol process combined with urea.
Keywords: Pt/C; electro catalyst; polyol process; urea hydrolysis.
Carbon-supported electro-catalysts are attracting high attention in fuel cell research
[1–4]. The performance of catalyst material strongly depends on its size distribution
and the loading [5–7]. Supported metal catalysts are often prepared by wet
impregnation and the ion adsorption, although these methods do not provide
adequate control on metal particle size and the distribution. Several reports on
the complexity of particle size control during high loadings are available from
the literature [8, 9]. Extensive investigations have been carried out to develop
alternate routes for preparing supported Pt catalysts. In those attempts, a stabilizing
agent was used to prevent the aggregation of metal particles during the nucleation
and adsorption steps. Organic stabilizers such as polyvinyl pyrolidine (PVP) and
To whom correspondence should be addressed. Tel.: (82-2) 2123-5753; Fax: (82-2) 312-6401;