The oscillation theory for liquid-liquid-gas reactions on a porous catalyst is considered in [1-3]. According to this theory, under some conditions the oscillatory motion of liquid in pores can take place due to the formation of gas or gas-vapor bubbles. Due to forced alternating motion of liquid, the reaction should run with the rate considerably higher than the rate predicted by the Thiele/Zeldovich model and, as a result, the temperature difference between the surface of the catalyst particle and its center (DeltaT) should also be higher. In this paper, the results of measuring DeltaT during the chemical reaction are presented. The experimental values of DeltaT occur to be 4-9 times more than the maximum possible values estimated by the Thiele/Zeldovich model. Such a significant distinction can be considered as a confirmation of the oscillation theory. (C) 2003 Elsevier B.V. All rights reserved.