Boundary in electrocatalytic hydrogen evolution reaction: From single metal to binary intermetallic compounds

Abstract

Ti2Cu, TiCu and TiCu4 were synthesized and their electrocatalytic activities for hydrogen evolution reaction (HER) were investigated. The hydrogen overpotential observed at 10 mA/ cm2 (η10) followed the order Ti2Cu (η10 = −215 mV) > TiCu (η10 = −182 mV) > TiCu4 (η10 = −170 mV). The hydrogen adsorption energy (∆GHad) on Cu site of TiCu4 is exergonic and close to optimal position (i.e. ∆GHad = 0). A synergistic effect was proposed to account for the excellent HER performance of these TiCu binary intermetallics compounds that could replace PGM and achieve Midas touch in the future.

Keywords

• Electrocatalysis
• Intermetallic compound
• Arc-melting
• Hydrogen evolution reaction
• Electronic band structure
• Density functional theory