Metallic PtC monolayer as a promising hydrogen evolution electrocatalyst

Abstract

Reasonable design of hydrogen evolution reaction (HER) electrocatalysts with low Pt loading and excellent catalytic performance is a key challenge in finding efficient and cost attractive catalysts. Pt with unique d-electron, which provides new opportunities for the development of HER catalysts when it forms compounds with C of high abundance on earth. Here, focusing on designing highly efficient catalysts composed of Pt and C elements by first-principles structure search simulations, identifying four stability PtCx monolayers. The novel PtC monolayer with zigzag C chain not only possesses lower Pt loading, but also shows inherent metallicity. Meanwhile, its H2O adsorption and dissociation abilities are efficient and easy. The HER activity of the PtC monolayer is comparable to the commercial Pt, e.g. desirable ΔGH* values and larger exchange current density, mainly attributing to lower charge donated of Pt, larger occupation of Pt PDOS at the Fermi level, and pair electrons of zigzag C chain. Moreover, its excellent HER activity can be maintained even at high H coverage under strain and solvent effect. All these attractive properties render the PtC monolayer an appropriate HER catalyst.