II International Symposium on Carbon for Catalysis ABSTRACTS

INVESTIGATION OF THE ELECTROCHEMICAL ACTIVITY OF
α-C/NOBLE METAL THIN FILM CATALYSTS
PP-I-1
Baranov A., Fanchenko S. 1 , Calliari L. 2 , Speranza G. 2 , Minati L. 2 , Fedoseenkov D. 3 ,
Shorokhov A.V. 3 , Nefedov A. 4
” MATI”-RGTU, Moscow, Russia
1 RRC Kurchatov Institute, Kurchatov Sq. 1, 123182 Moscow, Russia
2 ITC-irst, I-38050, Povo (Trento), Italy
3 Analitpribor, Smolensk, Russia
4 Ruhr-Universität Bochum, Bochum, Germany
e-mail: baranov@mccinet.ru
The sensitivity and selectivity of electrochemical gas sensors depends on several
parameters, such as the type of catalyst used, the working temperature, and the applied
electrical potential.
The traditional technology to produce gas permeable electrodes on porous substrates is
based on a mixture of C and powder catalysts, where the carbon role is to prevent the noble
metal grains from growing [1]. A disadvantage of this technology is the thickness of the
active catalytic layer (several tens of micrometers), which results in a high noble metal
consumption.
Amorphous carbon (α-C) thin films represent an alternative and perspective technology
to produce catalytic layers for electrodes to be used in electrochemical gas sensors. In this
case, the catalytic agent (for example, Pt nanoparticles) is co-deposited with C. Its relative
concentration in the film can be easily changed to increase it above the percolation
concentration, whereas the film thickness doesn’t typically exceed 2-4 nm [2]. This ensures
the required electrical conductivity and catalytic activity of the a-C/noble metal composite [3].
At the same time, the noble metal consumption is kept to a minimum.
In this work, plasma deposition is considered to produce thin catalyst films for
electrochemical gas sensors. The films are based on nano-composite carbon layers doped with
noble metals (Pt and Au). They were deposited ― on silicon wafers and porous Teflon
membranes ― by magnetron sputtering (MS) of graphite-Pt (Au) targets in Ar [4]. The
thickness of the layers ranged between 0.1 and 1 µm.
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