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In Situ Observation of Hydrogen‐Induced Surface Faceting for Palladium–Copper Nanocrystals at Atmospheric Pressure
Author(s) -
Jiang Ying,
Li Hengbo,
Wu Zhemin,
Ye Wenying,
Zhang Hui,
Wang Yong,
Sun Chenghua,
Zhang Ze
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201605956
Subject(s) - nanoreactor , faceting , nanocrystal , nanomaterial based catalyst , hydrogen , palladium , copper , atmospheric pressure , transmission electron microscopy , bar (unit) , catalysis , materials science , chemical physics , chemical engineering , nanotechnology , chemistry , crystallography , nanoparticle , metallurgy , organic chemistry , oceanography , physics , geology , meteorology , engineering
Abstract Nanocrystal (NC) morphology, which decides the number of active sites and catalytic efficiency, is strongly determined by the gases involved in synthesis, treatment, and reaction. Myriad investigations have been performed to understand the morphological response to the involved gases. However, most prior work is limited to low pressures, which is far beyond realistic conditions. A dynamic morphological evolution of palladium–copper (PdCu) NC within a nanoreactor is reported, with atmospheric pressure hydrogen at the atomic scale. In situ transmission electron microscopy (TEM) videos reveal that spherical PdCu particles transform into truncated cubes at high hydrogen pressure. First principles calculations demonstrate that the surface energies decline with hydrogen pressure, with a new order of γ H‐001 < γ H‐110 < γ H‐111 at 1 bar. A comprehensive Wulff construction based on the corrected surface energies is perfectly consistent with the experiments. The work provides a microscopic insight into NC behaviors at realistic gas pressure and is promising for the shaping of nanocatalysts by gas‐assisted treatments.