Affiliation:
1. Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborative Innovation Center of Biomedical Functional Materials School of Chemistry and Materials Science Nanjing Normal University Nanjing 210023 China
2. School of New Energy Nanjing University of Science and Technology Jiangyin Jiangsu 214443 China
3. Advanced Institute for Materials Research (WPI‐AIMR) Tohoku University Sendai 980‐8577 Japan
Abstract
AbstractPt‐based intermetallics are recognized as effective catalysts for oxygen reduction reaction (ORR) in fuel cells. However, the synthesis of intermetallics often requires prolonged annealing and the effect of different crystal structures on ORR still need to be investigated. Herein, L12‐Pt3Mn and L10‐PtMn intermetallics with Pt‐skin are rapidly synthesized through an emerging periodic carbothermal shock method to investigate their ORR‐activity difference. The formation of L12‐Pt3Mn and L10‐PtMn can be well‐controlled by the Pt/Mn feeding ratio, pulse cycles, and temperature. Electrocatalytic investigations show that L12‐Pt3Mn presents a more positive half‐wave potential (0.91 V vs RHE) and onset potential (1.02 V vs RHE) than those of L10‐PtMn. The mass activity and specific activity of L12‐Pt3Mn are respectively fourfold and threefold greater than those of L10‐PtMn. Theoretical calculations indicate that the L12‐Pt3Mn has a more substantial work function than L10‐PtMn, thereby conferring L12‐Pt3Mn with an increased electron density allocation for catalytic involvement. This electron confinement imparts L12‐Pt3Mn with a Pt d‐band center lower than that of L10‐PtMn, consequently attenuating the adsorption of strongly bonded *O intermediates during the rate‐determining step. This study not only employs a straightforward method for intermetallic preparation but also elucidates the discrepancies in ORR activity across intermetallics with distinct structures.
Funder
National Natural Science Foundation of China
Japan Society for the Promotion of Science
Iwatani Naoji Foundation
Subject
Electrochemistry,Condensed Matter Physics,Biomaterials,Electronic, Optical and Magnetic Materials