Energies (May 2019)

Applicability of a New Sulfonated Pentablock Copolymer Membrane and Modified Gas Diffusion Layers for Low-Cost Water Splitting Processes

  • S. Filice,
  • G. Urzì,
  • R. G. Milazzo,
  • S. M. S. Privitera,
  • S. A. Lombardo,
  • G. Compagnini,
  • S. Scalese

DOI
https://doi.org/10.3390/en12112064
Journal volume & issue
Vol. 12, no. 11
p. 2064

Abstract

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The aim of this work is to evaluate the possible use of Nexar™ polymer, a sulfonated pentablock copolymer (s-PBC), whose structure is formed by tert-butyl styrene, hydrogenated isoprene, sulfonated styrene, hydrogenated isoprene, and tert-butyl styrene (tBS-HI-SS-HI-tBS), as a more economical and efficient alternative to Nafion® membrane for proton exchange membrane (PEM) electrolysis cells. Furthermore, we have studied a new methodology for modification of gas diffusion layers (GDL) by depositing Pt and TiO2 nanoparticles at the cathode and anode side, respectively, and a protective polymeric layer on their surface, allowing the improvement of the contact with the membrane. Morphological, structural, and electrical characterization were performed on the Nexar™ membrane and on the modified GDLs. The use of modified GDLs positively affects the efficiency of the water electrolysis process. Furthermore, Nexar™ showed higher water uptake and conductivity with respect to Nafion®, resulting in an increased amount of current generated during water electrolysis. In conclusion, we show that Nexar™ is an efficient and cheaper alternative to Nafion® as the proton exchange membrane in water splitting applications and we suggest a possible methodology for improving GDLs’ properties. These results meet the urgent need for low-cost materials and processes for hydrogen production.

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