In the present work electrochemical methods, namely “cyclic voltammetry” and “in-situ catalyst potential measurements”, were applied for ex-situ and in-situ studies of catalysts respectively. Lactose oxidation was used as a model reaction. The combination of these two electrochemical methods gives a possibility for continuous characterization of metal containing heterogeneous catalysts during all steps of their life cycle – from synthesis to complete deactivation. The purpose of the ex-situ approach was to develop a common electrochemical method to characterize all VIII group metal catalysts. General steps, which can be used for every platinum group metal without making any specification or requirements on their nature, were elaborated. Second electrochemical method related to catalyst potential measurements, can provide in-situ information about surface processes in heterogeneous catalytic reactions. Catalyst potential curves can be used to indicate different surface processes. The...