Dirac Nodal Arc Semimetal PtSn4 : An Ideal Platform for Understanding Surface Properties and Catalysis for Hydrogen Evolution.

Guowei Li,Chenguang Fu,Abhay K Srivastava,Rana Saha,Jian Zhang,Vidya Madhavan,Xinliang Feng,Graeme R Blake,Mats Fahlman,Xianjie Liu,Gudrun Auffermann,Nitesh Kumar,Johannes Gooth,Wujun Shi,Machteld E Kamminga,Enke Liu,Lin Jiao,Yan Sun,Claudia Felser,Qun Yang,Jing Wu ,A Yazdani ,Stuart S P Parkin ,S Wirth

doi:10.1002/anie.201906109

Abstract

Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance of catalysts for a hydrogen evolution reaction (HER). However, it is a challenge to combine these factors into a single compound. Herein, we discover a superior electrocatalyst for a HER in the recently identified Dirac nodal arc semimetal PtSn4. The determined turnover frequency (TOF) for each active site of PtSn4 is 1.54 H2 s−1 at 100 mV. This sets a benchmark for HER catalysis on Pt‐based noble metals and earth‐abundant metal catalysts. We make use of the robust surface states of PtSn4 as their electrons can be transferred to the adsorbed hydrogen atoms in the catalytic process more efficiently. In addition, PtSn4 displays excellent chemical and electrochemical stabilities after long‐term exposure in air and long‐time HER stability tests.

Highlights

The hydrogen evolution reaction (2 H+ + 2 eÀ ! H2, HER) that occurs at the solid–liquid interface plays a vital role in clean energy conversion and for the understanding of other complicated heterogeneous reactions
Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance of catalysts for a hydrogen evolution reaction (HER)
The exposure of Sn atoms was considered

Summary

Introduction

The hydrogen evolution reaction (2 H+ + 2 eÀ ! H2, HER) that occurs at the solid–liquid interface plays a vital role in clean energy conversion and for the understanding of other complicated heterogeneous reactions. Of greater importance is the superior electrocatalytic stability of the single crystal after a long-time and high current density test The positive slope of the Hall resistivity as a function of applied magnetic field, as well as the positive thermopower (Figure S11b), indicate that the holes were the dominant charge carriers This ultrahigh conductivity and mobility may be derived from the unique Fermi surface and band dispersion of the PtSn4 single-crystal, which is a general characteristic of nodal arc semimetals. The downshift of hydrogen bands to a position far below the Fermi energy provided further proof of this electron transfer (Figure S21)

Conclusion

Conflict of interest