A catalytic micro-combustor using a pervaporation membrane as the passive methanol vaporizer is developed for direct methanol fuel cell (DMFC) applications, which is able to realize self-starting in an ambient environment. The methanol feed rate and the membrane diffusion coefficient related to the permeation flux are experimentally evaluated. Results indicate that the air feed rate (AFR) has positive effects on enhancing the methanol production and also increasing the catalyst temperature. A higher AFR promotes vapor generation and improves the combustion rate, thereby facilitating a higher start-up performance of the combustor. The infrared thermal analysis verifies the positive effect of increasing the AFR on the status of heat production and distribution. Results also validate the feasibility of changing the operating orientation of the combustor, which illuminates its potential use for portable applications. The online fuel cell tests validate that this combustor is viable to be used as a heat generator for a vapor-feed DMFC. (C) 2015 Elsevier B.V. All rights reserved.