An improved general understanding of electrocatalytic gas evolution reactions may - besides contributing to fundamental knowledge - play a crucial role in efforts directed to energy savings during large-scale industrial electrocatalytic processes. Aside from the search for new electrocatalytically active materials, in-depth understanding of electrode surface properties may contribute to more efficient utilization of known electrocatalysts. SECM is applied in the sample generation/tip collection mode to determine the spatial distribution of electrocatalytic activity during Cl-2 evolution at the solid/liquid interface of dimensionally stable anodes. Statistical interpretation of the local microscopic distribution of the electrocatalytic activity of dimensionally stable anodes was used as a basis for improved understanding of their overall electrocatalytic performance.