Activated Porous Highly Enriched Platinum and Palladium Electrocatalysts from Dealloyed Noncrystalline Alloys for Enhanced Hydrogen Evolution,ChemElectroChem

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Activated Porous Highly Enriched Platinum and Palladium Electrocatalysts from Dealloyed Noncrystalline Alloys for Enhanced Hydrogen Evolution
ChemElectroChem ( IF 3.5 ) Pub Date : 2020-10-12 , DOI: 10.1002/celc.202001230
Arti Sahu ₁ , Kallol Mondal ₂ , Raj Ganesh Pala _{1,

3}

Affiliation

Modulation of activity of a quasicrystalline or amorphous matrix by selective dealloying of a less reactive metal is a trade‐off between an activity increment due to enhanced electronic structure/surface area and an activity decrement due to an increase in crystallinity. We evaluate this trade‐off in melt‐spun ribbons of amorphous PtZr₄ and quasicrystalline PdZr₃ metallic glasses for the hydrogen evolution reaction (HER). Selective electrochemical dissolution of Zr generates highly porous, stable, predominantly Pt and Pd electrocatalysts and having three and eight times higher HER specific activity. Dealloyed Pt has two times higher specific HER activity than dealloyed Pd. The heat of mixing between Pt (Pd) and Zr is correlated to the extent of dealloying from PtZr₄ (PdZr₃) alloys. Dealloying glass‐forming element Zr enhances the activity of the resultant porous material due to the reduction in oxide layer formation and better optimized M−H bond strength. X‐ray photoelectron spectroscopy analysis suggests that activity enhancement is due to Pt/Pd atoms gaining a partial negative charge leading to the promotion of H⁺ absorption and an increase of HER activity upon dealloying. The present work also provides insight into the challenging search for a glass‐former that does not have a debilitating effect on the electronic structure of the noble metals.

中文翻译：

脱合金非结晶合金中的活化多孔高富集铂和钯电催化剂，可增强氢气释放

通过选择性地脱活反应性较低的金属来调节准晶态或非晶态基体的活性，是在由于电子结构/表面积增加而导致的活性增加与由于结晶度增加而导致的活性减少之间的权衡。我们评估了在无定形PtZr ₄和准晶体PdZr ₃金属玻璃的熔纺带中进行氢逸出反应（HER）的权衡。Zr的选择性电化学溶解产生高度多孔，稳定，主要为Pt和Pd的电催化剂，并具有3到8倍的HER比活性。脱金属铂的HER活性是脱金属钯的两倍。Pt（Pd）和Zr之间的混合热与PtZr _4的脱合金程度相关（PdZr ₃）合金。脱合金玻璃形成元素Zr通过减少氧化物层的形成和更好的优化MH键强度来增强所得多孔材料的活性。X射线光电子能谱分析表明，活性增强是由于Pt / Pd原子获得了部分负电荷，从而导致脱氢后H ⁺吸收的促进和HER活性的增加。本工作还提供了对寻找不影响贵金属电子结构的玻璃形成剂的挑战性见解。

更新日期：2020-11-03

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