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Title: The interaction of oxygen with high loaded Ru/{gamma}-Al{sub 2}O{sub 3} catalyst

Abstract

The interaction of oxygen with the Ru/{gamma}-Al{sub 2}O{sub 3} catalyst comprising metal particle with sizes of 1-16 nm, was examined over a temperature range 20-400 deg. C. The catalyst loaded with 10.8 wt.% Ru was prepared by incipient wetness from RuCl{sub 3} precursor. The structure of the Cl-containing catalyst and the catalyst after elimination Cl{sup -} ions was characterized using H{sub 2} and O{sub 2} chemisorption, O{sub 2} uptake, BET, XRD and TEM. The Cl{sup -} ions in the catalyst decreased the H{sub 2} and O{sub 2} chemisorption capacity of Ru and caused large discrepancies between the mean particle size calculated from gas chemisorption and from TEM. Exposure to O{sub 2} at 100-200 deg. C caused oxidation of small Ru particles, while larger particles were covered with very thin Ru{sub x}O{sub y} skin (undetected by XRD and TEM). The O/Ru ratio increased up to 200 deg. C implying high affinity of the small Ru particles to oxygen. Oxidation at 250 deg. C led to the formation of poorly crystalline RuO{sub 2} particles with a mean size of 4 nm, and coverage of large Ru particles with 1.6 nm thick oxide layer. At 300 and 400 deg. C crystallization of themore » RuO{sub 2} phase, as well as significant agglomeration of oxide particles was observed. However, even at 400 deg. C, metallic Ru was detected by XRD, TEM and SAED suggesting that large metal particles were not fully oxidized under the used conditions. Also, the O{sub 2} uptake at 400 deg. C was lower than expected for oxidation of Ru metal to RuO{sub 2}. For the catalyst after elimination Cl ions the O{sub 2} uptake (O/Ru ratio = 1.50) was higher, than for sample with large amount of Cl ions (O/Ru ratio = 1.34), indicating that the presence of Cl inhibits ruthenium oxidation in the Ru/Al{sub 2}O{sub 3} catalyst.« less

Authors:
 [1]
  1. Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wroclaw (Poland)
Publication Date:
OSTI Identifier:
21199669
Resource Type:
Journal Article
Journal Name:
Materials Research Bulletin
Additional Journal Information:
Journal Volume: 44; Journal Issue: 2; Other Information: DOI: 10.1016/j.materresbull.2008.05.018; PII: S0025-5408(08)00203-1; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0025-5408
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; CATALYSTS; CHEMISORPTION; CHLORINE IONS; CRYSTALLIZATION; ELECTRON DIFFRACTION; HYDROGEN; LAYERS; NANOSTRUCTURES; OXIDATION; PARTICLE SIZE; RUTHENIUM; RUTHENIUM CHLORIDES; RUTHENIUM OXIDES; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TRANSMISSION ELECTRON MICROSCOPY; UPTAKE; X-RAY DIFFRACTION

Citation Formats

Okal, Janina. The interaction of oxygen with high loaded Ru/{gamma}-Al{sub 2}O{sub 3} catalyst. United States: N. p., 2009. Web. doi:10.1016/j.materresbull.2008.05.018.
Okal, Janina. The interaction of oxygen with high loaded Ru/{gamma}-Al{sub 2}O{sub 3} catalyst. United States. https://doi.org/10.1016/j.materresbull.2008.05.018
Okal, Janina. 2009. "The interaction of oxygen with high loaded Ru/{gamma}-Al{sub 2}O{sub 3} catalyst". United States. https://doi.org/10.1016/j.materresbull.2008.05.018.
@article{osti_21199669,
title = {The interaction of oxygen with high loaded Ru/{gamma}-Al{sub 2}O{sub 3} catalyst},
author = {Okal, Janina},
abstractNote = {The interaction of oxygen with the Ru/{gamma}-Al{sub 2}O{sub 3} catalyst comprising metal particle with sizes of 1-16 nm, was examined over a temperature range 20-400 deg. C. The catalyst loaded with 10.8 wt.% Ru was prepared by incipient wetness from RuCl{sub 3} precursor. The structure of the Cl-containing catalyst and the catalyst after elimination Cl{sup -} ions was characterized using H{sub 2} and O{sub 2} chemisorption, O{sub 2} uptake, BET, XRD and TEM. The Cl{sup -} ions in the catalyst decreased the H{sub 2} and O{sub 2} chemisorption capacity of Ru and caused large discrepancies between the mean particle size calculated from gas chemisorption and from TEM. Exposure to O{sub 2} at 100-200 deg. C caused oxidation of small Ru particles, while larger particles were covered with very thin Ru{sub x}O{sub y} skin (undetected by XRD and TEM). The O/Ru ratio increased up to 200 deg. C implying high affinity of the small Ru particles to oxygen. Oxidation at 250 deg. C led to the formation of poorly crystalline RuO{sub 2} particles with a mean size of 4 nm, and coverage of large Ru particles with 1.6 nm thick oxide layer. At 300 and 400 deg. C crystallization of the RuO{sub 2} phase, as well as significant agglomeration of oxide particles was observed. However, even at 400 deg. C, metallic Ru was detected by XRD, TEM and SAED suggesting that large metal particles were not fully oxidized under the used conditions. Also, the O{sub 2} uptake at 400 deg. C was lower than expected for oxidation of Ru metal to RuO{sub 2}. For the catalyst after elimination Cl ions the O{sub 2} uptake (O/Ru ratio = 1.50) was higher, than for sample with large amount of Cl ions (O/Ru ratio = 1.34), indicating that the presence of Cl inhibits ruthenium oxidation in the Ru/Al{sub 2}O{sub 3} catalyst.},
doi = {10.1016/j.materresbull.2008.05.018},
url = {https://www.osti.gov/biblio/21199669}, journal = {Materials Research Bulletin},
issn = {0025-5408},
number = 2,
volume = 44,
place = {United States},
year = {Wed Feb 04 00:00:00 EST 2009},
month = {Wed Feb 04 00:00:00 EST 2009}
}