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Programmable Exposure of Pt Active Facets for Efficient Oxygen Reduction
Author(s) -
Wang Guanzhi,
Yang Zhenzhong,
Du Yingge,
Yang Yang
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201907322
Subject(s) - catalysis , anodizing , oxygen reduction , adsorption , electrochemistry , oxygen , porosity , platinum , chemical engineering , materials science , nanotechnology , chemistry , electrode , metallurgy , aluminium , organic chemistry , composite material , engineering
To produce efficient ORR catalysts with low Pt content, PtNi porous films (PFs) with sufficiently exposed Pt active sites were designed by an approach combining electrochemical bottom‐up (electrodeposition) and top‐down (anodization) processes. The dynamic oxygen‐bubble template (DOBT) programmably controlled by a square‐wave potential was used to tune the catalyst morphology and expose Pt active facets in PtNi PFs. Surface‐bounded species, such as hydroxyl (OH * , *=surface site) on the exposed PtNi PFs surfaces were adjusted by the applied anodic voltage, further affecting the dynamic oxygen (O 2 ) bubbles adsorption on Pt. As a result, PtNi PF with enriched Pt(111) facets (denoted as Pt 3.5 % Ni PF) was obtained, showing prominent ORR activity with an onset potential of 0.92 V (vs. RHE) at an ultra‐low Pt loading (0.015 mg cm −2 ).