In the work presented in this paper, a two-dimensional mathematical model of soot regeneration was developed for a single-channel catalytic diesel particulate filter. The commercial computational fluid dynamics (CFD) code ANSYS Fluent 15.0 was used to simulate the gas flow field, whereas the regeneration kinetics was implemented through user-defined-subroutines. Both mechanisms of catalyzed and non-catalyzed (i.e., thermal) oxidation were used to describe combustion of the soot trapped inside the porous wall of the filter. Conversely, only non-catalyzed oxidation was assumed for the cake layer. The aim of the work was at investigating the effect of the catalyst activity on the regeneration dynamics of the filter in the light of the thermal interaction between combustion of the soot in the (catalytic) porous wall and combustion of the cake. To this end, computations were run by increasing the pre-exponential factor in the Arrhenius equation for the catalytic reaction rate, thus simulating the effect of increasing catalyst activity. Numerical results have shown that, as the catalyst activity is increased, a transition occurs from a regime of slow combustion, in which regeneration proceeds in a substantially uniform manner over the filter, to a regime of intense combustion, in which regeneration proceeds by a reaction front moving upstream and downstream. The regime of slow combustion is characterized by low temperature rise (difference between the maximum filter temperature, T-max, and the inlet gas temperature, T-in, lower than 100 K) and long time for cake consumption and, thus, filter regeneration (similar to 1800 s). It is established when the catalyst activity is too low to appreciably affect combustion of the cake. Thus, combustion of the cake occurs independently of what happens in the porous wall of the filter. In contrast, the regime of intense combustion is characterized by high temperature rise - (T-max - T-in)similar to 400 K - and short time for regeneration (similar to 100 s). It is established when the catalyst activity is high enough to make the porous wall of the filter an effective pilot for the cake. For this regime, the highest temperature rise is found under conditions that maximize the synchronization between combustion of the soot in the porous wall of the filter and combustion of the cake. When such a synchronization is attained, the time for filter regeneration becomes substantially insensitive to variations in the catalyst activity. (C) 2015 Elsevier Ltd. All rights reserved.