Abstract
The pH-differential membraneless architecture could enhance the thermodynamic property and raise the electrochemical performance of a dual electrolyte microfluidic reactor (DEMR) for electrochemical conversion of CO2. Freed from hindrances of membrane structure and thermodynamic limitation, DEMR demonstrates the possibility of altering anolyte and catholyte pHs to achieve higher reactivity rates and efficiencies. Different operation condition parameters of a microfluidic network would affect the reactor performance to a certain extents, constraining further improvement. Therefore, we conducted experimental analysis to study the mechanisms and intrinsic correlations of catalyst to Nafion ratio, microchannel thickness, electrolyte flow rate and CO2 supply for an optimized outcome. A comprehensive investigation on the cell durability was also carried out in the way of repetitiveness and long period operation, regarding both reactivity and efficiency. It was found that the catalyst to Nafion ratio affects the performance in a parabolic relation and there exists optimal values of electrolyte flow rate and microfluidic channel thickness for maximized cell performance. The influence of the reactant CO2 supply rate is not significant above a certain level where kinetics limitation is not dominant. The parametric study provides an operational point of view on the dual electrolyte microfluidic reactor and serves as a tool for DEMR optimization design. (C) 2016 Elsevier Ltd. All rights reserved.