Isothermal desulfation of pre-sulfated Pt-BaO/γ-Al2O3 lean NOx trap catalysts with H2: the effect of H2 concentration and the roles of CO2 and H2O
Abstract
The desulfation mechanisms of pre-sulfated Pt-BaO/{gamma}-Al{sub 2}O{sub 3} lean NOx trap catalysts were investigated under isothermal conditions (600 C) using H{sub 2} as the reductant. Sulfates were found to be reduced first with H{sub 2} to produce SO{sub 2}, followed by a reaction between SO{sub 2} and H{sub 2} to produce H{sub 2}S. Gas analysis during the rich pulse reveals that the sulfur removal efficiency is initially proportional to the H{sub 2} concentration. At constant H{sub 2} concentration the overall desulfation efficiency decreases in the order of H{sub 2}/CO{sub 2}/H{sub 2}O > H{sub 2}/CO{sub 2} > H{sub 2}/H{sub 2}O > H{sub 2}, as confirmed by XPS analysis of residual sulfur in the desulfated samples. H{sub 2}O limits the evolution of SO{sub 2} at an early stage of the rich pulse and enhances the production of H{sub 2}S in later stages of reduction. CO{sub 2} is involved in both the formation of COS and the production of H{sub 2}O (via the reverse water-gas shift reaction), therefore, resulting in an increased overall efficiency.
- Authors:
- Publication Date:
- Research Org.:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1032678
- Report Number(s):
- PNNL-SA-78545
Journal ID: ISSN 0926-3373; ACBEE3; 35404; VT0401000; TRN: US201202%%278
- DOE Contract Number:
- AC05-76RL01830
- Resource Type:
- Journal Article
- Journal Name:
- Applied Catalysis. B, Environmental
- Additional Journal Information:
- Journal Volume: 111-112; Journal Issue: 1; Journal ID: ISSN 0926-3373
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES; CATALYSTS; EFFICIENCY; GAS ANALYSIS; PRODUCTION; REMOVAL; SULFATES; SULFUR; WATER GAS; X-RAY PHOTOELECTRON SPECTROSCOPY; Pt-BaO/γ-Al2O3; SO2; lean NOx trap; desulfation; H2S; COS; Environmental Molecular Sciences Laboratory
Citation Formats
Kim, Do Heui, Kwak, Ja Hun, Szanyi, Janos, and Peden, Charles HF. Isothermal desulfation of pre-sulfated Pt-BaO/γ-Al2O3 lean NOx trap catalysts with H2: the effect of H2 concentration and the roles of CO2 and H2O. United States: N. p., 2012.
Web. doi:10.1016/j.apcatb.2011.10.017.
Kim, Do Heui, Kwak, Ja Hun, Szanyi, Janos, & Peden, Charles HF. Isothermal desulfation of pre-sulfated Pt-BaO/γ-Al2O3 lean NOx trap catalysts with H2: the effect of H2 concentration and the roles of CO2 and H2O. United States. https://doi.org/10.1016/j.apcatb.2011.10.017
Kim, Do Heui, Kwak, Ja Hun, Szanyi, Janos, and Peden, Charles HF. 2012.
"Isothermal desulfation of pre-sulfated Pt-BaO/γ-Al2O3 lean NOx trap catalysts with H2: the effect of H2 concentration and the roles of CO2 and H2O". United States. https://doi.org/10.1016/j.apcatb.2011.10.017.
@article{osti_1032678,
title = {Isothermal desulfation of pre-sulfated Pt-BaO/γ-Al2O3 lean NOx trap catalysts with H2: the effect of H2 concentration and the roles of CO2 and H2O},
author = {Kim, Do Heui and Kwak, Ja Hun and Szanyi, Janos and Peden, Charles HF},
abstractNote = {The desulfation mechanisms of pre-sulfated Pt-BaO/{gamma}-Al{sub 2}O{sub 3} lean NOx trap catalysts were investigated under isothermal conditions (600 C) using H{sub 2} as the reductant. Sulfates were found to be reduced first with H{sub 2} to produce SO{sub 2}, followed by a reaction between SO{sub 2} and H{sub 2} to produce H{sub 2}S. Gas analysis during the rich pulse reveals that the sulfur removal efficiency is initially proportional to the H{sub 2} concentration. At constant H{sub 2} concentration the overall desulfation efficiency decreases in the order of H{sub 2}/CO{sub 2}/H{sub 2}O > H{sub 2}/CO{sub 2} > H{sub 2}/H{sub 2}O > H{sub 2}, as confirmed by XPS analysis of residual sulfur in the desulfated samples. H{sub 2}O limits the evolution of SO{sub 2} at an early stage of the rich pulse and enhances the production of H{sub 2}S in later stages of reduction. CO{sub 2} is involved in both the formation of COS and the production of H{sub 2}O (via the reverse water-gas shift reaction), therefore, resulting in an increased overall efficiency.},
doi = {10.1016/j.apcatb.2011.10.017},
url = {https://www.osti.gov/biblio/1032678},
journal = {Applied Catalysis. B, Environmental},
issn = {0926-3373},
number = 1,
volume = 111-112,
place = {United States},
year = {Thu Jan 12 00:00:00 EST 2012},
month = {Thu Jan 12 00:00:00 EST 2012}
}