Fractal dimension of electrochemical reactions

The reaction dimension of electrochemical processes was introduced as a quantitative factor for reactivity of catalysts. It is representative of the effective (reactive) surface area of the electrode for a catalytic reaction. Such a dimension can be estimated from the reaction efficiency at different particles sizes of the catalyst. The approach was proposed theoretically and was examined based on experimental results. For this purpose, three known electrochemical processes viz. electrochemical oxidation of methanol and of CO and electroreduction of O-2 at Pt particles were chosen as typical examples. The results obtained from experimental measurements showed the validity of the theory proposed. It was demonstrated that the approach proposed is not restricted to fractal surfaces and all catalysts with noninteger dimensions (due to the universal aspect of fractal geometry) can be considered. (C) 2004 The Electrochemical Society.