A Comparative Study of Alternative Polymer Binders for the Hydrogen Evolution Reaction

Given the economic, industrial, and environmental value of green dihydrogen (H2), optimization of water electrolysis as a means of producing H2 is essential. Binders are a crucial component of electrocatalysts, yet they remain largely underdeveloped, with a significant lack of standardization in the field. Therefore, targeted research into the development of alternative binder systems is essential for advancing performance and consistency. Binders essentially act as the key to regulating the electrode (support)–catalyst–electrolyte interfacial junctions and contribute to the overall reactivity of the electrocatalyst assembly. Therefore, alternative binders were explored with a focus on cost efficiency and environmental compatibility, striving to achieve desirable activity and stability. Herein, the alkaline hydrogen evolution reaction (HER) was investigated, and the sluggish water dissociation step was targeted. Controlled hydrophilic poly(vinyl alcohol)-based hydrogel binders were designed for this application. Three hydrogel binders were evaluated without incorporated electrocatalysts, namely PVA145, PVA145-blend-bPEI1.8, and PVA145-blend-PPy. Interestingly, the study revealed that the hydrophilicity of the binders exhibited an enhancing effect on the observed activity, resulting in improved performance compared to the commercial binder, Nafion™. Notably, the PVA145 system stands out, with an overpotential of 224 mV at−10 mA·cm−2 (geometric) in 1.0 M KOH, compared to the 238 mV exhibited by Nafion™. Inclusion of Pt as active material in PVA145 as binder exhibited a synergistic increase in performance, achieving a mass activity of 1.174 A.cm−2.mg−1 Pt in comparison to Nafion™’s 0.344 A.cm−2.mg−1 Pt, measured at−150 mV vs RHE. Our research aimed to contribute to the development of cost-effective and efficient binder systems, stressing the necessity to challenge the dominance of the commercially available binders.