The direct synthesis of hydrogen peroxide (DSH) from hydrogen and oxygen is an attractive production route due to its green nature. However, it faces multiple technical challenges, the biggest being the explosion risk of the flammable gas mixture. Herein we have used microreactors to perform the reaction in an inherently safer way which allows the hydrogen concentration to fall within the explosion limit range. For the first time, we have studied the flame propagation phenomena inside a microreactor to determine the optimum channel dimension for DSH. A mechanism of "fast synthesis and slow destruction" has been proposed via investigation on the influence of channel length and liquid flow rate. Besides, a variety of reaction parameters including gas flow rate, oxygen: hydrogen ratio, catalyst composition and gas pressure have been studied carefully. The successful employment of a microreactor in this case has indicated the potential of using micro reactors to inhibit the explosion risks of hazardous processes. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.