A numerical model for a microfluidic electrolytic cell (MEC) for CO2 utilization and fuel production is developed and validated against experimental data in literature. Mass transfer and electrochemical characteristics at the cathode of the MEC are studied. Limiting factors to the cell performance are found to be (i) low diffusivity of CO2 in the porous electrode, (ii) competing hydrogen evolution reaction (HER) at the cathode and (iii) dilution effect of hydrogen. Parametric effects are also studied to find strategies to optimize the cell performance. (c) 2012 Elsevier Ltd. All rights reserved.