Abstract
The identity of active species in supported gold catalysts for low temperature carbon monoxide oxidation remains an unsettled debate. With large amounts of experimental evidence supporting theories of either gold nanoparticles or sub-nm gold species being active, it was recently proposed that a size-dependent activity hierarchy should exist. Here we study the diverging catalytic behaviours after heat treatment of Au/FeO x materials prepared via co-precipitation and deposition precipitation methods. After ruling out any support effects, the gold particle size distributions in different catalysts are quantitatively studied using aberration corrected scanning transmission electron microscopy (STEM). A counting protocol is developed to reveal the true particle size distribution from HAADF-STEM images, which reliably includes all the gold species present. Correlation of the populations of the various gold species present with catalysis results demonstrate that a size-dependent activity hierarchy must exist in the Au/FeO x catalyst.
Original language | English |
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Article number | 12905 |
Journal | Nature Communications |
Volume | 7 |
DOIs | |
State | Published - Sep 27 2016 |
Funding
We gratefully acknowledge the Japanese Society for the Promotion of Science for fellowships to allow JKE (PE 10511) and SJF (PE 11562) to travel to Tokyo and carry out experiments in the lab of Professor Haruta. We also acknowledge support from Cardiff University as part of the MaxNet consortium. C.J.K. gratefully acknowledges funding from the National Science Foundation Major Research Instrumentation program (GR# MRI/DMR-1040229). Q.H. and A.Y.B. are supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division and through a user project supported by ORNLs Center for Nanophase Materials Sciences, sponsored by the Scientific User Facilities Division, Office of Science, Basic Energy Sciences, US Department of Energy.