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Title: Aqueous-phase reforming of methanol and ethanol to hydrogen on platinum-loaded NaY Zeolite catalysts.

Abstract

No abstract prepared.

Authors:
 [1];  [2]; ;  [3];  [4]
  1. (University of Cincinnati, Cincinnati, OH)
  2. (New Mexico Institiute of Mining and Technology, Socorro, NM)
  3. (New Mexico Institiute of Mining and Technology, Socorro, NM)
  4. (University of Cincinnati, Cincinnati, OH)
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
908880
Report Number(s):
SAND2007-2793J
TRN: US200722%%949
DOE Contract Number:
AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: Proposed for publication in Catalysis Communications.
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; 10 SYNTHETIC FUELS; CATALYSTS; ETHANOL; HYDROGEN; METHANOL; ZEOLITES; PLATINUM

Citation Formats

Dong, Junhang, Monroe, Justin, Nenoff, Tina Maria, Weinkauf, Donald, and Tang, Zhong. Aqueous-phase reforming of methanol and ethanol to hydrogen on platinum-loaded NaY Zeolite catalysts.. United States: N. p., 2007. Web.
Dong, Junhang, Monroe, Justin, Nenoff, Tina Maria, Weinkauf, Donald, & Tang, Zhong. Aqueous-phase reforming of methanol and ethanol to hydrogen on platinum-loaded NaY Zeolite catalysts.. United States.
Dong, Junhang, Monroe, Justin, Nenoff, Tina Maria, Weinkauf, Donald, and Tang, Zhong. Sun . "Aqueous-phase reforming of methanol and ethanol to hydrogen on platinum-loaded NaY Zeolite catalysts.". United States. doi:.
@article{osti_908880,
title = {Aqueous-phase reforming of methanol and ethanol to hydrogen on platinum-loaded NaY Zeolite catalysts.},
author = {Dong, Junhang and Monroe, Justin and Nenoff, Tina Maria and Weinkauf, Donald and Tang, Zhong},
abstractNote = {No abstract prepared.},
doi = {},
journal = {Proposed for publication in Catalysis Communications.},
number = ,
volume = ,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}
  • Bimetallic PdZn catalysts supported on carbon black (CB) and carbon nanotubes (CNTs) were found to be selective for CO-free H-2 production from ethanol at low temperature (250 degrees C). On Pd, the H-2 yield was low (similar to 0.3 mol H-2/mol ethanol reacted) and the CH4/CO2 ratio was high (similar to 1.7). Addition of Zn to Pd formed the intermetallic PdZn beta phase (atomic ratio of Zn to Pd is 1) with increased H-2 yield (similar to 1.9 mol H-2/mol ethanol reacted) and CH4/CO2 ratio of <1. The higher H-2 yield and low CH4 formation was related to the improvedmore » dehydrogenation activity of the L1(0) PdZn beta phase. The TOF increased with particle size and the CNTs provided the most active and selective catalysts, which may be ascribed to pore-confinement effects. Furthermore, no significant changes in either the supports or the PdZn beta particles was found after aqueous-phase reforming (APR) indicating that the metal nanoparticles and the carbon support are hydrothermally stable in the aqueous phase at elevated temperatures and pressures (>200 degrees C, 65 bar). No CO was detected for all the catalysts performed in aqueous-phase reaction, indicating that both monometallic Pd and bimetallic PdZn catalysts have high water-gas shift activity during APR. However, the yield of H-2 is considerably lower than the theoretical value of 6 H-2 per mole ethanol which is due to the presence of oxygenated products and methane on the PdZn catalysts.« less
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  • A novel oxidation reaction of CO with aqueous H{sub 2}O{sub 2} over Cu-NaY (2-15 wt%) and Ag-NaY (5-15 wt%) catalysts has been achieved at low temperatures (55-70 deg. C) using a flow mode system. The employed catalysts were prepared by the incipient wetness impregnation of NaY zeolite (Si/Al = 5.6, surface area = 910 m{sup 2}/g) with an aqueous solution of known concentrations of copper acetate and silver nitrate. Solids were subjected to thermal treatment at 300-450 deg. C prior to catalytic measurements unless subjected to subsequent reduction with hydrogen at 350 deg. C. The physicochemical characterization of the catalystsmore » was probed using X-ray diffraction (XRD), FT-IR and combined thermal analyses TGA-DrTGA. The XRD data indicated that, the Ag particles have an ordered location in the sodalite cavity and the center of a single six-ring. The FT-IR data also proved the presence of a new peak at 1385 cm{sup -1} that is assigned to Ag-coordinated with the framework. A slow induced oxidation of CO (induction period, t{sub ind}) took place at the initial stage of the CO oxidation reaction after which the reaction obeyed first-order kinetics. The utilized metal ions are proposed to be reduced to lower oxidation states such as Cu{sup +} and Ag{sup 0} during the first period of reaction, t{sub ind}, where the reaction proceeded favorably on such sites. Such argument was evidenced by carrying out the oxidation reaction over H{sub 2}-reduced Cu10-NaY and Ag10-NaY catalysts. The reduction caused a decrease in the t{sub ind}, giving an evidence that the lower oxidation states Cu{sup +} and Ag{sup 0} are the active sites in the studied oxidation reaction. The enhancement in catalytic activity was interpreted in terms of the facile adsorption of CO on the low oxidation state species.« less