Abstract: Pd/Al2O3 supported catalysts, differed in the initial structural and chemical states of palladium, were examined for the possible existence of self-sustained oscillations in the reaction of CO oxidation under temperature-programmed and isothermal modes using plug flow reactor at ambient pressure and CO and O2 concentration of 0.2 and 1.0 vol%, respectively. The supported samples after the action of reaction mixture were characterized using the HRTEM and XPS methods. The catalysts, calcined at relatively low temperatures 450 °C, cannot induce the self-sustained oscillation phenomena in the reaction of CO oxidation. The calcination at 800 °C yields highly dispersed particles of Pd0 and PdO in the catalysts with sizes varying between 2–3 and 10–20 nm, respectively. In this case self-sustained oscillations (SO) of the CO oxidation appeared in the region of middle CO conversions. In the catalyst calcined at 1000 °C, PdO is formed as large particles with sizes 20–100 nm. During prolonged self-sustained oscillations under isothermal conditions with varying CO concentrations in the reaction mixture, particles with “core–shell” structures are formed, where the cores are PdO and the shells are a Pd0 clusters ordered along a specific direction due to an epitaxy on PdO. Calcination at 1200 °C results in the formation of large Pd0 particles with sizes ≥200 nm. During prolonged self-sustained oscillations with varying CO concentrations under isothermal conditions, the reaction mixture causes destruction of the above particles to yield palladium particles with core–shell structures; in this case the cores are Pd0, and the shells are PdO layers.

Cite: Slavinskaya E.M. , Stonkus O.A. , Gulyaev R.V. , Ivanova A.S. , Zaikovskii V.I. , Kuznetsov P.A. , Boronin A.I.
Structural and Chemical States of Palladium in Pd/Al2O3 Catalysts under Self-Sustained Oscillations in Reaction of CO Oxidation
Applied Catalysis A: General. 2011. V.401. N1-2. P.83-97. DOI: 10.1016/j.apcata.2011.05.001 WOS Scopus РИНЦ ANCAN OpenAlex

Dates:

Submitted:	Mar 9, 2011
Accepted:	May 2, 2011
Published online:	May 7, 2011
Published print:	Jul 1, 2011

Identifiers:

Web of science:	WOS:000293492300010
Scopus:	2-s2.0-79959746282
Elibrary:	16984721
Chemical Abstracts:	2011:805114
Chemical Abstracts (print):	155:254019
OpenAlex:	W2002590374

Citing:

DB	Citing
Web of science	65
Scopus	63
Elibrary	70
OpenAlex	65

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