Ammonia decomposition reaction to produce COx free hydrogen over molybdenum incorporated mesoporous carbon based catalysts was studied in a microwave heated reactor system. Mesoporous carbon is acting as the catalyst support as well as the microwave receptor in the reaction medium. While the highest conversion value was 49% in conventionally heated reaction system at 600 degrees C, total conversion value was achieved over the same catalyst at 400 degrees C in microwave heated system with a GHSV of 36,000 ml/hg(cat). Transfer of microwave energy directly to the active particles, volumetric heating and hot spot formation are the main reasons of this great enhancement. While molybdenum nitride was observed under conventional heating, molybdenum carbide was formed in case of microwave application which could be another improving effect on catalytic activity of molybdenum incorporated mesoporous catalysts. (C) 2017 Elsevier B.V. All rights reserved.