Membrane electrode assembly simulation of anion exchange membrane water electrolysis

Abstract

Anion exchange membrane water electrolysis (AEMWE) offers a green hydrogen production method that eliminates the need for platinum group metals (PGM) as electrocatalysts. This study employs a COMSOL® 6.0 model to simulate a 1x1 cm2 Ni fibre − Raney® Ni || X37-50RT || NiFe2O4− SS316L fibre AEMWE membrane electrode assembly (MEA). The membrane is set at a thickness of 60μm, while the anodic and cathodic porous transport layers (PTL) are modelled with a thickness of 370μm, each having an average porosity of 0.70. The half−cell overpotentials are experimentally measured to validate the half−cell model in a three−electrode setup consisting of (working electrode) || AGAR-Ag/AgCl || Pt−wire (counter electrode). Two freshly prepared MEAs validated the (i) base case and (ii) sensitivity analysis models. The base case model validated the MEA results at 20 °C and 1 atm in 1M KOH electrolyte feed at 1.56 ml min−1 cm−2. The five parameters studied with the sensitivity analysis revealed the most influential parameters based on area-specific resistance (ASR) change in the following order (＋ and − indicate increase and decrease in ASR, respectively): KOH concentration (−97%), membrane thickness (＋ 9%), temperature (−4%), cathode feed type (<+0.5%), and KOH flow rate (>−0.5%).