title: High-Indexed Pt3Ni Alloy Tetrahexahedral Nanoframes Evolved through Preferential CO Etching.
abstract: Chemically controlling crystal structures in nanoscale is challenging, yet provides an effective way to improve catalytic performances. Pt-based nanoframes are a new class of nanomaterials that have great potential as high-performance catalysts. To date, these nanoframes are formed through acid etching in aqueous solutions, which demands long reaction time and often yields ill-defined surface structures. Herein we demonstrate a robust and unprecedented protocol for facile development of high-performance nanoframe catalysts using size and crystallographic facet-controlled PtNi4tetrahexahedral nanocrystals prepared through a colloidal synthesis approach as precursors. This new protocol employs the Mond process to preferentially dealloy nickel component in the ⟨100⟩ direction through carbon monoxide etching of carbon-supported PtNi4tetrahexahedral nanocrystals at an elevated temperature. The resultant Pt3Ni alloy tetrahexahedral nanoframes possess an open, stable, and high-indexed microstructure, containing a segregated Pt thin layer strained to the Pt-Ni alloy surfaces and featuring a down-shift d-band center as revealed by the density functional theory calculations. These nanoframes exhibit much improved catalytic performance, such as high stability under prolonged electrochemical potential cycles, promoting direct electro-oxidation of formic acid to carbon dioxide and enhancing oxygen reduction reaction activities. Because carbon monoxide can be generated from the carbon support through thermal annealing in air, a common process for pretreating supported catalysts, the developed approach can be easily adopted for preparing industrial scale catalysts that are made of Pt-Ni and other alloy nanoframes.
authors.affiliation: Department of Chemistry, State University of New York at Binghamton , Binghamton, New York 13902, United States.
authors.forename: Chenyu
authors.initials: C
authors.lastname: Wang
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States.
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States.
authors.forename: Hongzhou
authors.initials: H
authors.lastname: Yang
authors.affiliation: Materials Science and Engineering Program, State University of New York at Binghamton , Binghamton, New York 13902, United States.
authors.forename: Jinfong
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Physics, Arizona State University , Tempe, Arizona 85287, United States.
authors.forename: Jingyue
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States.
authors.forename: Charles
authors.initials: C
authors.lastname: Dotse
authors.affiliation: Department of Chemistry, State University of New York at Binghamton , Binghamton, New York 13902, United States.
authors.forename: Yiliang
authors.initials: Y
authors.lastname: Luan
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan, Shanxi 030001, China.|Synfuels China Co. Ltd., Huairou, Beijing 101407, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Chemistry, University of South Dakota , Vermillion, South Dakota 57069, United States.
authors.forename: Cuikun
authors.initials: C
authors.lastname: Lin
authors.affiliation: College of Chemical Engineering, China University of Petroleum , Qingdao, Shandong 266580, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Nanotechnology Systems Division, Hitachi High Technologies America, Inc., Clarksburg, Maryland 20871, United States.
authors.forename: James P
authors.initials: JP
authors.lastname: Kilcrease
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan, Shanxi 030001, China.|Synfuels China Co. Ltd., Huairou, Beijing 101407, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wen
authors.affiliation: Department of Chemistry and Biochemistry, Miami University , Oxford, Ohio 45056, United States.|Department of Chemistry, American University , Washington, District of Columbia 20016, United States.
authors.forename: Shouzhong
authors.initials: S
authors.lastname: Zou
authors.affiliation: Department of Chemistry, State University of New York at Binghamton , Binghamton, New York 13902, United States.|Materials Science and Engineering Program, State University of New York at Binghamton , Binghamton, New York 13902, United States.
authors.forename: Jiye
authors.identifier: 0000-0003-3703-3204
authors.initials: J
authors.lastname: Fang
keywords: Nanoframe; Pt3Ni; high-index; preferential etching; tetrahexahedron