By means of reactor modeling, externally cooled tubular reactors equipped with metallic honeycombs as catalyst supports are investigated. A 2D pseudo-continuous reactor model is adopted to study in particular heat transfer properties and to identify the influencing parameters as well as transport processes on the reactor performance. It is found that honeycomb reactors can indeed be operated isothermally up to higher cooling temperatures in comparison to fixed-bed reactors. The reduced catalyst inventory, however, prevents attaining thermodynamic equilibrium at low temperatures. Exceeding cooling temperatures adequate for isothermal operation, moderate hot spots can be maintained in a narrow range of cooling temperatures before transition to maximum temperatures in excess of 500 degrees C.