H3PO4-imbibed three-dimensional polyacrylamide/polyacrylamide hydrogel as a high-temperature proton exchange membrane with excellent acid retention

Abstract

We herein report the use of polyacrylamide/polyacrylamide interpenetrating polymer network (PAM/PAM IPN) hydrogel as a matrix to imbibe proton conducting H₃PO₄, forming a robust proton exchange membrane (PEM) suitable for high-temperature PEM fuel cells by combining excellent acid retention, simple synthesis, and low cost. Its extraordinary ability to absorb large quantity of aqueous solution is fully utilized to achieve high H₃PO₄ loading, showing a proton conductivity of 0.0833 S cm⁻¹ at 183 °C in dry air. The synthesized membrane also shows excellent acid retention even under mechanical load and high humidity. These profound advantages along with simple and low-cost synthesis promise the new membrane to be a strong candidate as a high-temperature PEM.