• Kamaroddin, M.F.A.^a,b, Sabli, N.^a,d,Nia, P.M.^b, Abdullah, T.A.T.^b,c,Abdullah, L.C.^a,Izhar, S.^a, Ripin, A.^b,c, Ahmad, A.^b,c

• ^aDepartment of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia
• ^bCentre of Hydrogen Energy, Institute of Future Energy, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia
• ^cSchool of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia
• ^dInstitute of Advanced Technology (ITMA), Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia

Abstract

A copper chloride (CuCl) electrolyzer that constitutes of composite proton exchange membrane (PEM) that functions at medium-temperature (>100 °C) is beneficial for rapid electrochemical kinetics and better in handling fuel pollutants. A synthesized polybenzimidazole (PBI) composite membrane from the addition of ZrO₂ followed with phosphoric acid (PA) is suggested to overcome the main issues in CuCl electrolysis, including the copper diffusion and proton conductivity. PBI/ZrP properties improved significantly with enhanced proton conductivity (3 fold of pristine PBI, 50% of Nafion 117), superior thermal stability (>600 °C), good mechanical strength (85.17 MPa), reasonable Cu permeability (7.9 × 10⁻⁷) and high ionic exchange capacity (3.2 × 10⁻³ mol g⁻¹). Hydrogen produced at 0.5 A cm⁻² (115 °C) for PBI/ZrP and Nafion 117 was 3.27 cm³ min⁻¹ and 1.85 cm³ min⁻¹, respectively. The CuCl electrolyzer efficiency was ranging from 91 to 97%, thus proven that the hybrid PBI/ZrP membrane can be a promising and cheaper alternative to Nafion membrane. © 2019 Hydrogen Energy Publications LLC