Designing binary electrocatalysts for hydrogen evolution in saline electrolyte using rapid synthesis on carbon paper supports

Abstract

Generating hydrogen from brackish or seawater could enable flexible energy generation, de-centralized electricity storage, and decreased reliance on energy-intensive water purification for the hydrogen evolution reaction (HER). Platinum is often the most effective electrocatalyst for HER, however it is not as stable or efficient in nonideal electrolytes, such as seawater or non-acidic media. In this work, we investigate the activity and stability of binary electrocatalysts in a brackish neutral electrolyte. Using a rapid carbon-paper-based electrochemical synthesis method, we systematically assessed 45 unary and binary electrocatalysts. Four standout binary electrocatalyst materials were identified that showed either comparable or superior activity and stability to Pt in saline-containing electrolyte. Most notably, the 1Ni:1Pt electrocatalyst had a similar overpotential (60 mV) to a Pt control (50 mV), but with greater stability. Finally, we show that this carbon-paper-based synthesis method is scalable for synthesizing and assessing electrocatalysts. This work provides important insight both for rapid synthesis and comparison of new electrocatalysts, as well as for the specific goal of performing HER in non-ideal aqueous conditions.