Yang Qun, Li Guowei, Manna Kaustuv, Fan Fengren, Felser Claudia, Sun Yan
Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden, 01187, Germany.
Center for Nanoscale Systems, Faculty of Arts and Sciences, Harvard University, Oxford Str. 11, LISE 308, Cambridge, MA, 02138, USA.
Adv Mater. 2020 Apr;32(14):e1908518. doi: 10.1002/adma.201908518. Epub 2020 Feb 20.
It has been demonstrated that topological nontrivial surface states can favor heterogeneous catalysis processes such as the hydrogen evolution reaction (HER), but a further decrease in mass loading and an increase in activity are still highly challenging. The observation of massless chiral fermions associated with large topological charge and long Fermi arc (FA) surface states inspires the investigation of their relationship with the charge transfer and adsorption process in the HER. In this study, it is found that the HER efficiency of Pt-group metals can be boosted significantly by introducing topological order. A giant nontrivial topological energy window and a long topological surface FA are expected at the surface when forming chiral crystals in the space group of P2 3 (#198). This makes the nontrivial topological features resistant to a large change in the applied overpotential. As HER catalysts, PtAl and PtGa chiral crystals show turnover frequencies as high as 5.6 and 17.1 s and an overpotential as low as 14 and 13.3 mV at a current density of 10 mA cm . These crystals outperform those of commercial Pt and nanostructured catalysts. This work opens a new avenue for the development of high-efficiency catalysts with the strategy of topological engineering of excellent transitional catalytic materials.
已经证明，拓扑非平凡表面态有利于析氢反应（HER）等多相催化过程，但进一步降低质量负载并提高活性仍然极具挑战性。与大拓扑电荷和长费米弧（FA）表面态相关的无质量手性费米子的观测激发了对它们与HER中电荷转移和吸附过程关系的研究。在本研究中，发现通过引入拓扑序可以显著提高铂族金属的HER效率。当在空间群P2 3（#198）中形成手性晶体时，预计在表面会出现巨大的非平凡拓扑能量窗口和长拓扑表面FA。这使得非平凡拓扑特征能够抵抗外加过电位的大幅变化。作为HER催化剂，PtAl和PtGa手性晶体在电流密度为10 mA cm 时，周转频率高达5.6和17.1 s ，过电位低至14和13.3 mV。这些晶体优于商业铂和纳米结构催化剂。这项工作为采用优异过渡催化材料的拓扑工程策略开发高效催化剂开辟了一条新途径。
