Comparative Study of Electrochemical Methods for Determination of Methanol Permeation Through Proton-Exchange Membranes

Abstract

In this work, methanol permeation rates were measured using various electrochemical techniques, namely, cyclic voltammetry, chronoamperometry and potentiometry. For all the methods, a Nafion ® 117 membrane was used to measure and evaluate methanol crossover rates. The purpose of this study is to compare the methanol permeation data obtained using the above-mentioned techniques under identical conditions, compare the data with the literature data, and then suggest the most accurate and reliable method for the determination of methanol crossover rates. The permeability values using these techniques were found to be in the range 1.11 × 10 −6 to 1.27 × 10 −6 cm 2 /s. The permeability values obtained using these techniques are close to one another and also compare well with the literature data for similar conditions; however, after careful screening of the data, it was found that the potentiometric technique is the easiest in terms of experimentation, reproducibility of results and accuracy, and gives more data points. This technique is suggested to be the best and most accurate for studying methanol permeation rates through membranes for direct methanol fuel cell applications.

Sulfonated poly (ether ether ketone)/MOF hybrid polymer electrolyte membrane with ultra‐low methanol permeability for enhanced direct methanol fuel cell performance

“…This substantial reduction is attributed to the well‐rigid structure of the MOF, which effectively blocks the methanol permeation within the SPEEK matrix. Furthermore, increasing the MOF content creates a tortuous path within the membrane, further restricting methanol permeation 21,51 . Overall results clearly indicate that the prepared hybrid membrane is excellent methanol barrier than commercial Nafion.…”

A Robust Composite Proton Exchange Membrane of Sulfonated Poly (Fluorenyl Ether Ketone) with an Electrospun Polyimide Mat for Direct Methanol Fuel Cells Application

“…V and C 0 are the volume (cm 3 ) and initial concentration (mol L −1 ) of the methanol solution, respectively. Δ C /Δ t is the slope of the methanol concentration varying with time in the water compartment [ 36 , 37 , 38 ]. The set-up is shown in Figure S3 .…”

“…Taking PI@SPFEK composite as an example. References [ 36 , 37 , 38 ] are cited in the supplementary materials.…”