Electrification of endothermic reactions has the potentialto provide a compact and flexible reactor concept, and at the same time, substantially reduce CO2 emissions relative to combustion-heated processes. Here, we show how integrated electrical heating using a wash-coated catalytic structure can resolve limiting thermal conductivity acrossthe catalyst. The inherent uniform supply of heat enables engineeringof catalytic efficiency to desired values by changing wash-coat thickness.Overall, the approach diminishes catalytic efficiency as a limitingdesign parameter. Instead, coat thickness will relate to catalyst lifetime, as very thin coats are more susceptible to deactivation. Characteristic time-scale analysis indicates heat transfer to be theleast limiting mechanism, and reactor performance is instead governed by diffusion. Optimal performance based on fluid dynamic simulations favors internal diameters below 0.5 mm, and high linear gas velocities, toward alleviating mass transfer limitations. Integrated electrical heated steam methane reforming essentially inverts the order of reaction mechanisms compared to conventional reforming, challenging the constraintsof current industrial practice.