Loading…
The decomposition of mixed oxide Ag2Cu2O3: Structural features and the catalytic properties in CO and C2H4 oxidation
[Display omitted] •High reactivity of Ag2Cu2O3 causes its decomposition into Ag0 and CuO.•Ensemble of oriented Ag0 nanoparticles is formed during Ag2Cu2O3 decomposition.•Ag0/CuO interface exhibits catalytic properties in CO oxidation and C2H4 epoxidation. The mixed silver-copper oxide Ag2Cu2O3 with...
Saved in:
Published in: | Applied surface science 2018-01, Vol.427, p.363-374 |
---|---|
Main Authors: | , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | [Display omitted]
•High reactivity of Ag2Cu2O3 causes its decomposition into Ag0 and CuO.•Ensemble of oriented Ag0 nanoparticles is formed during Ag2Cu2O3 decomposition.•Ag0/CuO interface exhibits catalytic properties in CO oxidation and C2H4 epoxidation.
The mixed silver-copper oxide Ag2Cu2O3 with a paramelaconite crystal structure is a promising material for catalytic applications. The as-prepared sample of Ag2Cu2O3 consisted of brick-like particles extended along the [001] direction. A combination of physicochemical techniques such as TEM, XPS and XRD was applied to investigate the structural features of this mixed silver-copper oxide. The thermal stability of Ag2Cu2O3 was investigated using in situ XRD under different reaction conditions, including a catalytic CO+O2 mixture. The first step of Ag2Cu2O3 decomposition was accompanied by the appearance of ensembles consisting of silver nanoparticles with sizes of 5–15nm. Silver nanoparticles were strongly oriented to each other and to the surface of the initial Ag2Cu2O3 bricks. Based on the XRD data, it was shown that the release of silver occurred along the a and b axes of the paramelaconite structure. Partial decomposition of Ag2Cu2O3 accompanied by the formation of silver nanoparticles was observed during prolonged air storage under ambient conditions. The high reactivity is discussed as a reason for spontaneous decomposition during Ag2Cu2O3 storage. The full decomposition of the mixed oxide into metallic silver and copper (II) oxide took place at temperatures higher than 300°C regardless of the nature of the reaction medium (helium, air, CO+O2). Catalytic properties of partially and fully decomposed samples of mixed silver-copper oxide were measured in low-temperature CO oxidation and C2H4 epoxidation reactions. |
---|---|
ISSN: | 0169-4332 1873-5584 |
DOI: | 10.1016/j.apsusc.2017.08.010 |