Jeong Sangmin, Branco Anthony J, Bollen Silas W, Sullivan Connor S, Ross Michael B
Department of Chemistry, University of Massachusetts Lowell, Lowell, MA 01854, USA.
Nanoscale. 2024 Jun 20;16(24):11530-11537. doi: 10.1039/d4nr01538j.
The creation of electrocatalysts with reduced concentrations of platinum-group metals remains a critical challenge for electrochemical hydrogen production. High-entropy alloys (HEAs) offer a distinct type of catalyst with tunable compositions and engineered surface activity, significantly enhancing the hydrogen evolution reaction (HER). We present the synthesis of AuPdFeNiCo HEA nanoparticles (NPs) using a wet impregnation method. The composition and structure of the AuPdFeNiCo HEA NPs are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HR-TEM). These nanoparticles exhibit robust HER performance quantified over a broad pH range, with higher activity than any of the unary metal counterparts in all pHs. In comparison to a commercial 10%Pt/C electrocatalyst, AuPdFeNiCo HEA NPs exhibit enhanced electrochemical activity in both acidic and alkaline electrolytes at a current density of 10 mA cm. Additionally, these nanoparticles achieve a current density of 100 mA cm at a voltage of 540 mV in neutral electrolytes, outperforming Pt/C which requires 570 mV. These findings help enable broad use of reduced precious metal electrocatalysts for water electrolysis in a variety of water and pH conditions.
制备铂族金属浓度降低的电催化剂仍然是电化学制氢面临的一项关键挑战。高熵合金（HEA）提供了一种独特类型的催化剂，其成分可调且表面活性可设计，能显著增强析氢反应（HER）。我们展示了采用湿浸渍法合成AuPdFeNiCo高熵合金纳米颗粒（NP）。通过X射线衍射（XRD）、X射线光电子能谱（XPS）和高分辨率透射电子显微镜（HR-TEM）对AuPdFeNiCo高熵合金纳米颗粒的成分和结构进行了表征。这些纳米颗粒在很宽的pH范围内都表现出强劲的析氢反应性能，在所有pH值下其活性都高于任何一种单一金属对应物。与商用10%Pt/C电催化剂相比，在10 mA cm的电流密度下，AuPdFeNiCo高熵合金纳米颗粒在酸性和碱性电解质中均表现出增强的电化学活性。此外，这些纳米颗粒在中性电解质中在540 mV的电压下实现了100 mA cm的电流密度，优于需要570 mV的Pt/C。这些发现有助于在各种水质和pH条件下广泛使用贵金属含量降低的电催化剂进行水电解。
