東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Model catalysts prepared by size-sel...

Aizawa, Masato.

Linked to FindBook

Google Book

Amazon

博客來

Model catalysts prepared by size-selected nanocluster deposition.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Model catalysts prepared by size-selected nanocluster deposition./
Author:	Aizawa, Masato.
Description:	159 p.
Notes:	Source: Dissertation Abstracts International, Volume: 64-03, Section: B, page: 1258.
Contained By:	Dissertation Abstracts International64-03B.
Subject:	Chemistry, Physical. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3084585

Model catalysts prepared by size-selected nanocluster deposition.
Aizawa, Masato.

Model catalysts prepared by size-selected nanocluster deposition. - 159 p.

Source: Dissertation Abstracts International, Volume: 64-03, Section: B, page: 1258.

Thesis (Ph.D.)--The University of Utah, 2003.

Catalytic activity and product selectivity of supported metal catalysts strongly depend on the size of metal particles, support materials, and preparation methods. A novel instrument was employed to investigate electronic structure, morphology, and chemical properties of the model supported catalysts.{09}Size- and energy-selected metal clusters containing fewer than 30 atoms on TiO 2 (110) were characterized by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), ion scattering spectroscopy (ISS), and temperature programmed desorption (TPD). The performance of the instrument was checked with investigating the oxidation of vanadium and niobium clusters supported on TiO2 (110).Subjects--Topical Terms:

560527
Chemistry, Physical.

Model catalysts prepared by size-selected nanocluster deposition.
LDR:03300nmm 2200301 4500 001 1864609
005 20041216132629.5
008 130614s2003 eng d
035 $a (UnM)AAI3084585
035 $a AAI3084585
040 $a UnM $c UnM
100 1 $a Aizawa, Masato. $3 1952091
245 1 0 $a Model catalysts prepared by size-selected nanocluster deposition.
300 $a 159 p.
500 $a Source: Dissertation Abstracts International, Volume: 64-03, Section: B, page: 1258.
500 $a Adviser: Scott L. Anderson.
502 $a Thesis (Ph.D.)--The University of Utah, 2003.
520 $a Catalytic activity and product selectivity of supported metal catalysts strongly depend on the size of metal particles, support materials, and preparation methods. A novel instrument was employed to investigate electronic structure, morphology, and chemical properties of the model supported catalysts.{09}Size- and energy-selected metal clusters containing fewer than 30 atoms on TiO 2 (110) were characterized by X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), ion scattering spectroscopy (ISS), and temperature programmed desorption (TPD). The performance of the instrument was checked with investigating the oxidation of vanadium and niobium clusters supported on TiO2 (110).
520 $a Ni clusters are in the zero oxidation state on the support at low impact energies. Oxidation, however, occurs either when increasing the impact energy or when chemisorbed oxygen being available at oxygen defect sites of TiO 2. The small clusters bind preferentially to oxygen sites. The large clusters appear to retain some three dimensional structure on the support. For these clusters, no obvious desorption features were observed in the temperature range above 140K. The lack of CO desorption is interpreted in terms of strong Ni cluster-TiO2 binding. It seems that the nickel clusters are sintering and/or are encapsulated during the TPD experiments.
520 $a Ir clusters are also in the zero oxidation state on the support irrespective of the cluster size and the impact energies. At low impact energies the clusters stay more or less intact on the support. The clusters embed themselves into the support at higher impact energies. The threshold energy for the embedding is lower for the larger clusters. This system shows pronounced substrate-mediated adsorption (SMA) of CO at low doses, with the effect varying inversely with cluster size. CO adsorbed via SMA at low CO dose is bound differently from that at high CO dose. In experiments with sequential C16O and C18O doses, C16O → C18O exchange was observed for all cluster sizes, and the amount of exchange increased with the C18O dose. The peak CO desorption temperature was found to decrease with increasing cluster size. In addition, the CO desorption intensity decreases with increasing deposition energy, consistent with the ISS data showing that the iridium clusters tend to embed into the support at elevated impact energies.
590 $a School code: 0240.
650 4 $a Chemistry, Physical. $3 560527
650 4 $a Chemistry, Inorganic. $3 517253
650 4 $a Engineering, Materials Science. $3 1017759
690 $a 0494
690 $a 0488
690 $a 0794
710 2 0 $a The University of Utah. $3 1017410
773 0 $t Dissertation Abstracts International $g 64-03B.
790 1 0 $a Anderson, Scott L., $e advisor
790 $a 0240
791 $a Ph.D.
792 $a 2003
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3084585