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Observation and Identification of an Atomic Oxygen Structure on Catalytic Gold Nanoparticles
Author(s) -
Liu Kai,
Chen Tao,
He Shuyue,
Robbins Jason P.,
Podkolzin Simon G.,
Tian Fei
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201706647
Subject(s) - catalysis , raman spectroscopy , oxygen , colloidal gold , chemistry , dimer , nanoparticle , decomposition , dispersity , atom (system on chip) , photochemistry , crystallography , inorganic chemistry , nanotechnology , materials science , polymer chemistry , organic chemistry , embedded system , physics , computer science , optics
Interactions between oxygen and gold surfaces are fundamentally important in diverse areas of science and technology. In this work, an oxygen dimer structure was observed and identified on gold nanoparticles in catalytic decomposition of hydrogen peroxide to oxygen and water. This structure, which is different from isolated atomic or molecular oxygen surface structures, was observed with in situ surface‐enhanced Raman spectroscopic measurements and identified with density functional theory calculations. The experimental measurements were performed using monodisperse 5, 50 and 400 nm gold particles supported on silica with liquid‐phase hydrogen and deuterium peroxides at multiple pH values. The calculations show that on surfaces with coordinatively unsaturated gold atoms, two oxygen atoms preferentially share a gold atom with a bond distance of 0.194–0.196 nm and additionally bind to two other surface gold atoms with a larger bond distance of 0.203–0.213 nm, forming an Au‐O‐Au‐O‐Au structure. The formation of this structure depends on reaction rates and conditions.