UNT Libraries Government Documents Department - 23 Matching Results

Search Results

Results: 1 - 23
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: During this quarter, we continued to study the X-ray absorption spectra of copper oxide sorbents exposed to flue gases as a function of temperature. Our purpose was to investigate in more detail the transformation occurring above 200 C. We report here a series of in situ EXAFS and XANES measurements for CuO/A[sub 2]O[sub 3] sorbents and model compounds. We investigated the evolution of the structure at the Cu site as a function of temperature in the presence or absence of flue gases. Below we d… more
Date: 1989
Creator: Cooper, B.R. & Montano, P.A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: During this quarter we studied the X-ray absorption spectra of copper oxides compounds exposed to flue gases. Model compounds were used as standards for our sorbents. We also continued growing CuO single crystals using a variety of approaches; the first samples obtained were too small to be of any use (1 mm). The EELS measurements were continued on the CuO sorbents. The spectra of oxidized Cu(100) were measured over a wide range of coverage and temperature. We measured in situ the Cu K-edge abs… more
Date: 1989
Creator: Cooper, B.R. & Montano, P.A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: During this quarter, we continued to study the X-ray absorption spectra of copper compounds. Here we report measurements of the high resolution XANES and EXAFS spectra at the sulfur K-edge (E=2472 eV). Using these results together with the information from other investigations, we attempted to gain a better understanding of the complicated chemical adsorption process taking place on the CuO/Al[sub 2]O[sub 3] surface. In the modeling work we have made a major modification of our methodology that… more
Date: 1989
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]

Description: Removal of SO2 from flue gas is major problem in use of coal for electric power generation. CuO on Al2O3 can be used as a regenerable SO2 adsorbent for flue-gas cleanup. Modeling study indicated that success of CuO on Al2O3 probably depends on the O-Cu bonding energy being lower than that of O-Al; hence, the sorbent should be operated at low temperature where the hydroxyl ions render the Al sites ineffective. Measurements show that the sorbent with 7% Cu loading is more efficient than 5% for Cu… more
Date: 1991
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: RHEED (reflection high energy electron diffraction) was carried out on Cu(110) at 153 to 973 K. Specular spot profiles show decreased scattering intensity around 550 K. RHEED patterns show disappearance of Kikuchi lines above 800 K. LEED indicate anharmonicities on Cu(110) surface at high temperatures. Results suggest that anharmonic effects precede onset of a rough surface at about 800 K. Three possible models were investigated for the clean surface for copper oxide dispersed on alumina; one w… more
Date: 1990
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: During this quarter we continued to study the x-ray absorption spectra of copper oxide sorbents exposed to flue gases as a function of temperature. Our purpose was to investigate in more detail the transformation occurring above 200C. Unfortunately we had only one week of beam time, and we were therefore limited in the number of in situ runs. We continued growing CuO single crystals using a variety of approaches. The samples obtained are still too small to be useful. We studied the lattice dyna… more
Date: 1989
Creator: Cooper, B.R. & Montano, P.A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: During this quarter, we studied the x-ray absorption spectra of CaO and CaSO[sub 4] at high temperatures and used standard models to determine the calcium environment during coal combustion. The theoretical effort during this quarter was directed toward modeling the electronic structure of CuO supported on alumina; this is necessary for understanding the chemisorption processes for surface oxide and nitrogen oxide components of flue gas. 8 figs.
Date: 1988
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: We performed XANES and EXAFS measurements at the sulfur K-edge for FeS, CuS and two coals, Powhatan [number sign]5 and Blacksville [number sign]2. We have used the measurements of the two standards in discussing the spectra of the spectra of the two coals as described below. We have continued our investigation for the possible bonding configurations of the SO[sub 2] molecule on CuO/Al[sub 2]O[sub 3]. In distinction to sulfur-to-metal (S-M) on-top bonding, we find that oxygen-to-metal (O-M) on-t… more
Date: 1990
Creator: Cooper, B.R. & Montano, P.A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO[sub x] and NO[sub x]]

Description: Work this quarter was devoted to initiating the coordinated experimental and theoretical/computational modeling study of CuO dispersed on alumina for adsorption of sulfur oxide gases. Research was devoted to characterizing CuO itself, as well as sulfur model compounds for benchmark comparisons, and toward modeling of copper site locations for dispersion on alumina.
Date: 1988
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}. Final technical report

Description: Removal of SO2 from flue gas is major problem in use of coal for electric power generation. CuO on Al2O3 can be used as a regenerable SO2 adsorbent for flue-gas cleanup. Modeling study indicated that success of CuO on Al2O3 probably depends on the O-Cu bonding energy being lower than that of O-Al; hence, the sorbent should be operated at low temperature where the hydroxyl ions render the Al sites ineffective. Measurements show that the sorbent with 7% Cu loading is more efficient than 5% for Cu… more
Date: 1991
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, December 1, 1988--February 28, 1989

Description: During this quarter we studied the X-ray absorption spectra of copper oxides compounds exposed to flue gases. Model compounds were used as standards for our sorbents. We also continued growing CuO single crystals using a variety of approaches; the first samples obtained were too small to be of any use (1 mm). The EELS measurements were continued on the CuO sorbents. The spectra of oxidized Cu(100) were measured over a wide range of coverage and temperature. We measured in situ the Cu K-edge abs… more
Date: 1989
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, December 1, 1989--February 28, 1990

Description: RHEED (reflection high energy electron diffraction) was carried out on Cu(110) at 153 to 973 K. Specular spot profiles show decreased scattering intensity around 550 K. RHEED patterns show disappearance of Kikuchi lines above 800 K. LEED indicate anharmonicities on Cu(110) surface at high temperatures. Results suggest that anharmonic effects precede onset of a rough surface at about 800 K. Three possible models were investigated for the clean surface for copper oxide dispersed on alumina; one w… more
Date: 1990
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, June 1, 1989--August 31, 1989

Description: During this quarter, we continued to study the X-ray absorption spectra of copper oxide sorbents exposed to flue gases as a function of temperature. Our purpose was to investigate in more detail the transformation occurring above 200 C. We report here a series of in situ EXAFS and XANES measurements for CuO/A{sub 2}O{sub 3} sorbents and model compounds. We investigated the evolution of the structure at the Cu site as a function of temperature in the presence or absence of flue gases. Below we d… more
Date: 1989
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, June 1--August 31, 1988

Description: During this quarter, we studied the x-ray absorption spectra of CaO and CaSO{sub 4} at high temperatures and used standard models to determine the calcium environment during coal combustion. The theoretical effort during this quarter was directed toward modeling the electronic structure of CuO supported on alumina; this is necessary for understanding the chemisorption processes for surface oxide and nitrogen oxide components of flue gas. 8 figs.
Date: 1988
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, March 1, 1989--May 31, 1989

Description: During this quarter we continued to study the x-ray absorption spectra of copper oxide sorbents exposed to flue gases as a function of temperature. Our purpose was to investigate in more detail the transformation occurring above 200C. Unfortunately we had only one week of beam time, and we were therefore limited in the number of in situ runs. We continued growing CuO single crystals using a variety of approaches. The samples obtained are still too small to be useful. We studied the lattice dyna… more
Date: 1989
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, March 1, 1990--May 31, 1990

Description: We performed XANES and EXAFS measurements at the sulfur K-edge for FeS, CuS and two coals, Powhatan {number_sign}5 and Blacksville {number_sign}2. We have used the measurements of the two standards in discussing the spectra of the spectra of the two coals as described below. We have continued our investigation for the possible bonding configurations of the SO{sub 2} molecule on CuO/Al{sub 2}O{sub 3}. In distinction to sulfur-to-metal (S-M) on-top bonding, we find that oxygen-to-metal (O-M) on-t… more
Date: 1990
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, September 1, 1989--November 30, 1989

Description: During this quarter, we continued to study the X-ray absorption spectra of copper compounds. Here we report measurements of the high resolution XANES and EXAFS spectra at the sulfur K-edge (E=2472 eV). Using these results together with the information from other investigations, we attempted to gain a better understanding of the complicated chemical adsorption process taking place on the CuO/Al{sub 2}O{sub 3} surface. In the modeling work we have made a major modification of our methodology that… more
Date: 1989
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface studies of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, September 1--November 30, 1988

Description: Work this quarter was devoted to initiating the coordinated experimental and theoretical/computational modeling study of CuO dispersed on alumina for adsorption of sulfur oxide gases. Research was devoted to characterizing CuO itself, as well as sulfur model compounds for benchmark comparisons, and toward modeling of copper site locations for dispersion on alumina.
Date: 1988
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

Surface study of absorbents for the removal of SO{sub x} and NO{sub x}. [First quarterly report, March 1--May 31, 1988]

Description: The objective of this program is to obtain an understanding of the crystallographic and electronic structure of the active sites on supported oxides which are used in the removal of S0{sub 2} and NO{sub x} from flue gases. This understanding will be used to help in the development of new metal oxide sorbents with enhanced effectiveness towards the removal of deleterious gases from combustion products. Such successful sorbent development will further the goals of DOE`s Flue Gas Cleanup Program, … more
Date: 1988
Creator: Cooper, B. R. & Montano, P. A.
Item Type: Refine your search to only Report
open access

[Surface study of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, December 1, 1990--February 28, 1991

Description: X-ray absorption spectra were measured on two CuO/Al{sub 2}O{sub 3} samples with 5 and 7% Cu loadings, at RT to 300 C. Flue gas was from Kentucky {number_sign}5 coal burned in a small combustor. Measurements were completed on single-crystal CuO, confirming that the single-crystal behavior has no significant implications for understanding the adsorption mechanism of SO{sub 2} on CuO/Al{sub 2}O{sub 3}. Modeling effort confirmed the previous tentative conclusion that the most favorable circumstanc… more
Date: 1991
Creator: Cooper, B. R. & Montano, P.
Item Type: Refine your search to only Report
open access

[Surface study of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, June 1, 1990--August 31, 1990

Description: XANES and EXAFS measurements were made on a CuO/Al{sub 2}O{sub 3} sample which went through a complete reaction cycle with flue gases, followed by comparison with pure CuO. In the modeling studies, of the possible bridging type adsorption configurations for the SO{sub 2} molecule on CuO/Al{sub 2}O{sub 3}, the only one yielding SO{sub 2} adsorption of possible practical interest is that for the SO{sub 2} molecule bridging a Cu and an Al atom with the molecule bent away from the surface; the bond… more
Date: 1990
Creator: Cooper, B. R. & Montano, P.
Item Type: Refine your search to only Report
open access

[Surface study of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, March 1--June 30, 1991

Description: We have completed our modeling survey of the possibility of using zinc oxide rather than copper oxide dispersed on alumina. This does not look promising. We found that for the zinc system, the ``on-top`` and ``side-on`` models for the adsorption of SO{sub 2} do not show any chemisorption binding, while the ``bridge`` site model shows only a weak chemisorption. We initiated a modeling survey for the use of molybdenum oxide. We have completed our modeling survey of the possibility of using molybd… more
Date: August 1993
Creator: Cooper, B. R. & Montano, P.
Item Type: Refine your search to only Report
open access

[Surface study of absorbents for the removal of SO{sub x} and NO{sub x}]. Quarterly report, September 1, 1990--November 30, 1990

Description: XANES spectra are given for a number of model sulfur-containing compounds. The XANES and EXAFS spectra and structures of the inorganic standards (CuSO{sub 4}, FeS{sub 2}, FeS, CuS) are discussed. Calculations were made on SO{sub 2} adsorption on CuO/Al{sub 2}O{sub 3} surface; results show that the SO{sub 2} is adsorbed on the surface via O-Cu bonding, probably in the form of a ``bridge`` with the two oxygen atoms of SO{sub 2}sitting at two surface metal atoms. It is probably better to have low-… more
Date: 1990
Creator: Cooper, B. R. & Montano, P.
Item Type: Refine your search to only Report
Back to Top of Screen