II International Symposium on Carbon for Catalysis ABSTRACTS

PP-<strong>II</strong>-21
THE USE OF ACTIVATED CARBON AS THE SUPPORT OF BIMETALLIC
CATALYSTS USED IN CO OXIDATION AND CO HYDROGENATION
Özkara S., Çağlayan B.S., Avcı B.K., Z. Önsan Z.I., Aksoylu A.E.
Department of Chemical Engineering, Boğaziçi University,34342 Bebek, Istanbul, Turkey
e-mail: aksoylu@boun.edu.tr
Activated carbon (AC) is a high surface area support with a very unique property. its
textural and surface chemical properties can be changed by a simple treatment like oxidation;
these changes affect the properties of the resultant catalysts prepared with AC. This paper is
an overview of the studies conducted in Catalyst Technology and Reaction Engineering Lab
(CATREL) at Boğaziçi University.
Previous studies on AC support and AC supported catalysts had clearly shown the effects
of different oxidation treatments on both the chemical and physical properties of AC and
catalytic properties of the catalysts [1-3]. The results of CO oxidation and benzene
hydrogenation tests conducted on Pt-Sn/AC had pointed out to the changes in metal
dispersion, the formation of a Pt-rich alloy, Pt 3 Sn, and the resultant high activity in CO
oxidation, all of which stems from the formation of oxygen bearing surface groups, especially
acidic groups, on oxidized AC.
The current paper concerns the use of AC support in the catalysts for CO oxidation in
hydrogen rich streams and CO hydrogenation. Bimetallic Pt-Ce and Pt-Sn systems has been
tested for CO oxidation as the continuation of the previous studies mentioned [1-3]; this time
CO oxidation activity of the AC supported catalysts were tested for hydrogen rich streams [4].
Another bimetallic system, Ni-Mo, had been tested in CO hydrogenation previously where
Al 2 O 3 has been used as the support [5-7]. In the current study was used the Ni-Mo system on
AC supports. The results clearly indicate the beneficial use of AC as the support. Both in CO
oxidation and hydrogenation catalysts, three types of activated carbon, namely (i) grinded and
HCl washed activated carbon (AC1), (ii) air oxidized form of AC1 (AC2), and (iii) HNO 3
oxidized form of AC1 (AC3), were prepared and used as catalyst supports.
CO oxidation in H 2 -rich streams: The selective oxidation of CO in a H 2 -rich gas stream
was investigated over a series of Pt-Ce and Pt-Sn catalysts supported on activated carbon
(AC). The results have shown that the activities of AC supported catalysts increased with the
increase in reduction temperature. Higher conversion levels were observed for 1% CeO x -1%
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