Electrochemical Dealloying of PdCu₃ Nanoparticles to Achieve Pt‐like Activity for the Hydrogen Evolution Reaction

Abstract

Manipulating the d-band center of the metal surface and hence optimizing the free energy of hydrogen adsorption (ΔG ) close to the optimal adsorption energy (ΔG =0) for hydrogen evolution reaction (HER), is an efficient strategy to enhance the activity for HER. Herein, we report a oleylamine-mediated (acting as the solvent, stabilizer, and reducing agent) strategy to synthesize intermetallic PdCu nanoparticles (NPs) without using any external reducing agent. Upon electrochemical cycling, PdCu transforms into Pd-rich PdCu (ΔG =0.05 eV), exhibiting remarkably enhanced activity (with a current density of 25 mA cm at ∼69 mV overpotential) as an alternative to Pt for HER. The first-principle calculation suggests that formation of low coordination number Pd active sites alters the d-band center and hence optimal adsorption of hydrogen, leading to enhanced activity. This finding may provide guidelines towards the design and development of Pt-free highly active and robust electrocatalysts.

Rational strain engineering in delafossite oxides for highly efficient hydrogen evolution catalysis in acidic media

“…S3 for details). These values are close to dealloyed Pd nanoparticles without normalization for real surface area (0.18 mA/cm²) 52 To provide insights into the origin of the currents observed in the electrocatalytic experiments, the evolution of hydrogen was investigated close to the surface by scanning electrochemical microscopy (SECM) measurements on PdCoO 2 single crystals operando (see Fig. S4 a & b for illustration).…”

Mesoporous Carbon with Different Density of Thiophenic‐Like Functional Groups and Their Effect on Oxygen Reduction

“…Pt nanoparticles (NPs) are ubiquitously employed in electrocatalytic processes such as electrooxidation of organic acids, alcohols, and carbon monoxide, reduction of nitrogen to ammonia, hydrogen evolution, hydrogen oxidation reaction (HOR), and O 2 reduction reaction (ORR) . HOR and ORR play a key role in the development of fuel‐cell devices, in which ORR is more sluggish than HOR, thus determining the kinetics of the whole process.…”

Perspective on intermetallics towards efficient electrocatalytic water-splitting

“…81 Although a variety of intermetallic compounds have been synthesized under such conditions and applied for manifold applications, their utilization as electrocatalysts for water splitting is rather limited. [126][127][128][129] Recently, intermetallic NiMo with a surface containing SiO was obtained in reducing hydrothermally grown NiMoO 4 . in the H 2 atmosphere.…”