Catalytic activity of Ni3Mo surfaces for hydrogen evolution reaction: A density functional theory approach

Highlights: • The hydrogen evolution reaction (HER) on four Ni₃Mo surfaces was examined by DFT. • Ni₃Mo(1 0 1) displayed the fastest water dissociation (1^st Volmer step in the HER). • Ni₃Mo(1 0 1) is more HER-active than Ni₃Mo(1 0 0), (0 2 0), or (0 0 1). • H-adsorption on Ni₃Mo(1 0 1) has a Gibbs fress energy of −0.224 eV, close to that of Pt(1 1 1). • Ni₃Mo(1 0 1) should display excellent HER performance as a non-noble metal catalyst. Ni₃Mo alloys are promising non-platinum group metal catalyst candidates for hydrogen evolution reactions in alkaline solution. The Volmer step for the hydrogen evolution reaction in alkaline medium was examined using density functional theory (DFT). We examined hydrogen adsorption on Ni₃Mo surfaces [(0 0 1), (0 2 0), (1 0 0), and (1 0 1)]. Ni₃Mo(1 0 1) showed the fastest dissociation of water in the first step of the HER among the investigated Ni₃Mo surfaces. Hydrogen atom chemisorption was a key reaction that determines HER performance; the adsorption free energies revealed that Ni₃Mo(1 0 1) has a higher electrocatalytic activity than the other surfaces of Ni₃Mo. Our work provides insight into the excellent HER catalytic performance of Ni₃Mo in alkaline solution and is expected to inform the design of efficient binary non-PGM catalyst for the HER.