Metal-modified niobium carbides as low-cost and impurity-resistant electrocatalysts for hydrogen evolution in acidic and alkaline electrolytes

Abstract

Low-cost and impurity-resistant electrocatalysts for the hydrogen evolution reaction (HER) are desired to replace expensive bulk Pt in membrane electrolysis cells. Monolayer (ML) Pt, Pd, and Ag on niobium carbide (NbC) thin films were synthesized for electrochemical testing as HER catalyst candidates. Density Functional Theory calculations predicted that ML Pt on NbC binds hydrogen similarly to bulk Pt, suggesting good HER activity. These results were confirmed through electrochemical measurements in both acidic and alkaline electrolytes. The Pt/NbC catalyst also maintained its activity in the presence of common impurity ions found in tap water. This makes ML Pt/NbC a promising replacement for Pt in water electrolysis cell cathodes. Future work on high surface area powders should be performed to further assess its suitability as a catalyst for membrane electrolyzers.