The management of heat of reactions in a packed‐bed catalytic reactor is “a priori” during the design and operation of such system. In the case of extremely exothermic reaction, the improvement in heat transfer will assure reactor stability and prevent runaway and explosion. Two experimental schemes were selected to study quantitatively the effectiveness of heat transfer improvement. Within the range of present experimentation, the improvement in terms of percentage increase in kermay be as high as 40% in case of mixed particle bed. In the case of square‐wave cyclic operations in gas flow, this improvement ranges between 4 to 10% increase in kerdepending on the magnitude of particle Reynolds number.