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Title: Exploring low-temperature dehydrogenation at ionic Cu sites in beta zeolite to enable alkane recycle in dimethyl ether homologation

Abstract

Cu-based catalysts containing targeted functionalities including metallic Cu, oxidized Cu, ionic Cu, and Bronsted acid sites were synthesized and evaluated for isobutane dehydrogenation. Hydrogen productivities, combined with operando X-ray absorption spectroscopy, indicated that Cu(I) sites in Cu/BEA catalysts activate C-H bonds in isobutane. Computational analysis revealed that isobutane dehydrogenation at a Cu(I) site proceeds through a two-step mechanism with a maximum energy barrier of 159 kJ/mol. Furthermore, these results demonstrate that light alkanes can be reactivated on Cu/BEA, which may enable re-entry of these species into the chain-growth cycle of dimethyl ether homologation, thereby increasing gasoline-range (C 5+) hydrocarbon yield.

Authors:
 [1];  [1]; ORCiD logo [1];  [2];  [3];  [4];  [1]; ORCiD logo [4]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Purdue Univ., West Lafayette, IN (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. National Renewable Energy Lab. (NREL), Golden, CO (United States); Colorado School of Mines, Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B)
OSTI Identifier:
1357736
Report Number(s):
NREL/JA-5100-67284
Journal ID: ISSN 2155-5435
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Catalysis
Additional Journal Information:
Journal Volume: 7; Journal Issue: 5; Journal ID: ISSN 2155-5435
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; copper; C-H activation; dehydrogenation; heterogeneous catalysis; zeolites

Citation Formats

Farberow, Carrie A., Cheah, Singfoong, Kim, Seonah, Miller, Jeffrey T., Gallagher, James R., Hensley, Jesse E., Schaidle, Joshua A., and Ruddy, Daniel A. Exploring low-temperature dehydrogenation at ionic Cu sites in beta zeolite to enable alkane recycle in dimethyl ether homologation. United States: N. p., 2017. Web. doi:10.1021/acscatal.6b03582.
Farberow, Carrie A., Cheah, Singfoong, Kim, Seonah, Miller, Jeffrey T., Gallagher, James R., Hensley, Jesse E., Schaidle, Joshua A., & Ruddy, Daniel A. Exploring low-temperature dehydrogenation at ionic Cu sites in beta zeolite to enable alkane recycle in dimethyl ether homologation. United States. doi:10.1021/acscatal.6b03582.
Farberow, Carrie A., Cheah, Singfoong, Kim, Seonah, Miller, Jeffrey T., Gallagher, James R., Hensley, Jesse E., Schaidle, Joshua A., and Ruddy, Daniel A. 2017. "Exploring low-temperature dehydrogenation at ionic Cu sites in beta zeolite to enable alkane recycle in dimethyl ether homologation". United States. doi:10.1021/acscatal.6b03582.
@article{osti_1357736,
title = {Exploring low-temperature dehydrogenation at ionic Cu sites in beta zeolite to enable alkane recycle in dimethyl ether homologation},
author = {Farberow, Carrie A. and Cheah, Singfoong and Kim, Seonah and Miller, Jeffrey T. and Gallagher, James R. and Hensley, Jesse E. and Schaidle, Joshua A. and Ruddy, Daniel A.},
abstractNote = {Cu-based catalysts containing targeted functionalities including metallic Cu, oxidized Cu, ionic Cu, and Bronsted acid sites were synthesized and evaluated for isobutane dehydrogenation. Hydrogen productivities, combined with operando X-ray absorption spectroscopy, indicated that Cu(I) sites in Cu/BEA catalysts activate C-H bonds in isobutane. Computational analysis revealed that isobutane dehydrogenation at a Cu(I) site proceeds through a two-step mechanism with a maximum energy barrier of 159 kJ/mol. Furthermore, these results demonstrate that light alkanes can be reactivated on Cu/BEA, which may enable re-entry of these species into the chain-growth cycle of dimethyl ether homologation, thereby increasing gasoline-range (C5+) hydrocarbon yield.},
doi = {10.1021/acscatal.6b03582},
journal = {ACS Catalysis},
number = 5,
volume = 7,
place = {United States},
year = 2017,
month = 4
}

Journal Article:
Free Publicly Available Full Text
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  • The excess molar enthalpies at 323.15 K, 373.15 K, and 423.15 K, at 8 MPa, are reported for the binary mixtures methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + poly(ethylene glycol) dimethyl ether 250 (PEGDME 250). Excess molar enthalpies were determined with a Setaram C-80 calorimeter equipped with a flow mixing cell. For both systems, the excess enthalpies are positive over the whole composition range, increasing with temperature. The H{sup E}(x) curves are slightly asymmetrical, and their maxima are skewed toward the methanol-rich region. The excess enthalpies slightly change with the pressure, the sign of this change beingmore » composition-dependent. In the case of mixtures with TEGDME, the experimental H{sup E} values have been compared with those predicted with the Gmehling et al. version of UNIFAC (Dortmund) and the Nitta-Chao and DISQUAC group contribution models.« less
  • The sorption of dimethyl ether in zeolite H-rho was studied by deuterium NMR of the deuteriated sorbate. The line shapes depend strongly on the temperature and the loading. These changes are not due to dynamic line-broadening effects but rather to changing distributions of sites with different modes of motion. At low loading levels the molecules are rigidly bound and can be seen to undergo 180/sup 0/ flips about the C/sub 2v/ axes. When the number of sorbed molecules exceeds that of the available acid sites (12 per unit cell) most of the molecules appear to be in a physisorbed state.
  • CO hydrogenation has been studied over Pd/NaY and Pd/HY catalysts prepared by ion exchange, By controlling the calcination program, Pd/NaY catalysts can be tuned to selectively produce either branched C{sub 4} hydrocarbons or CH{sub 3}OH and CH{sub 3}OCH{sub 3}. On Pd/HY catalysts, C{sub 2}H{sub 6} and C{sub 3}H{sub 8} predominate. Dissociative adsorption of CO over small Pd particles leads to formation of methane and an interstitial PdC{sub 0.13} compound, detected by XRD. Reduction with H{sub 2} converts PdC{sub 0.13} to Pd and methane. During CO hydrogenation catalysis, palladium particles grow, leading to local collapse of the zeolite lattice. Pd migrationmore » is also manifest from changes in the Pd/Si ratio detected by XPS. The reaction network reveals bifunctional catalysis: formation of CH{sub 3}OH on Pd particles is followed by its conversion to CH{sub 3}OCH{sub 3} and hydrocarbons over acid sites. Readsorption of hydrocarbons on the Pd particles results in hydrogenation of unsaturated compounds and to changes in the activity, selectivity, and deactivation behavior of the catalysts.« less