title: Electrochemical Dealloying of PdCu3Nanoparticles 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 (ΔGH) close to the optimal adsorption energy (ΔGH=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 PdCu3nanoparticles (NPs) without using any external reducing agent. Upon electrochemical cycling, PdCu3transforms into Pd-rich PdCu (ΔGH=0.05 eV), exhibiting remarkably enhanced activity (with a current density of 25 mA cm-2at ∼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.
authors.affiliation: New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, India.
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Jana
authors.affiliation: New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, India.
authors.forename: Anupam
authors.initials: A
authors.lastname: Bhim
authors.affiliation: New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, India.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Bothra
authors.affiliation: New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, India.|Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, India.
authors.forename: Swapan K
authors.initials: SK
authors.lastname: Pati
authors.affiliation: New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, India. sebastiancp@jncasr.ac.in.
authors.forename: Sebastian C
authors.identifier: http://orcid.org/0000-0002-5211-446X
authors.initials: SC
authors.lastname: Peter
mesh_terms: D000497:Alloys / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D006859:Hydrogen / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010165:Palladium / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D010984:Platinum / Q000737:chemistry*; D033362:Powder Diffraction
chemical_list: D000497:Alloys; D010984:Platinum; D010165:Palladium; D003300:Copper; D006859:Hydrogen
keywords: electrochemical dealloying; hydrogen absorption; hydrogen evolution reaction; nanoparticles; platinum-free catalyst