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Title: Temperature-programmed deoxygenation of acetic acid on molybdenum carbide catalysts

Abstract

Temperature programmed reaction (TPRxn) is a simple yet powerful tool for screening solid catalyst performance at a variety of conditions. A TPRxn system includes a reactor, furnace, gas and vapor sources, flow control, instrumentation to quantify reaction products (e.g., gas chromatograph), and instrumentation to monitor the reaction in real time (e.g., mass spectrometer). Here, we apply the TPRxn methodology to study molybdenum carbide catalysts for the deoxygenation of acetic acid, an important reaction among many in the upgrading/stabilization of biomass pyrolysis vapors. TPRxn is used to evaluate catalyst activity and selectivity and to test hypothetical reaction pathways (e.g., decarbonylation, ketonization, and hydrogenation). Furthermore, the results of the TPRxn study of acetic acid deoxygenation show that molybdenum carbide is an active catalyst for this reaction at temperatures above ca. 300 °C and that the reaction favors deoxygenation (i.e., C-O bond-breaking) products at temperatures below ca. 400 °C and decarbonylation (i.e., C-C bond-breaking) products at temperatures above ca. 400 °C.

Authors:
 [1];  [1];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B)
OSTI Identifier:
1348874
Report Number(s):
NREL/JA-5100-66811
Journal ID: ISSN 1940-087X; jove
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Visualized Experiments
Additional Journal Information:
Journal Volume: 2017; Journal Issue: 120; Journal ID: ISSN 1940-087X
Publisher:
MyJoVE Corp.
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; micro-scale; reactor; upgrading; acetic acid; catalyst; model compound; gas chromatography; temperature-programmed reaction; chemistry; Issue 120; mass spectrometry; molybdenum carbide

Citation Formats

Nash, Connor P., Farberow, Carrie A., and Hensley, Jesse E. Temperature-programmed deoxygenation of acetic acid on molybdenum carbide catalysts. United States: N. p., 2017. Web. doi:10.3791/55314.
Nash, Connor P., Farberow, Carrie A., & Hensley, Jesse E. Temperature-programmed deoxygenation of acetic acid on molybdenum carbide catalysts. United States. doi:10.3791/55314.
Nash, Connor P., Farberow, Carrie A., and Hensley, Jesse E. Tue . "Temperature-programmed deoxygenation of acetic acid on molybdenum carbide catalysts". United States. doi:10.3791/55314. https://www.osti.gov/servlets/purl/1348874.
@article{osti_1348874,
title = {Temperature-programmed deoxygenation of acetic acid on molybdenum carbide catalysts},
author = {Nash, Connor P. and Farberow, Carrie A. and Hensley, Jesse E.},
abstractNote = {Temperature programmed reaction (TPRxn) is a simple yet powerful tool for screening solid catalyst performance at a variety of conditions. A TPRxn system includes a reactor, furnace, gas and vapor sources, flow control, instrumentation to quantify reaction products (e.g., gas chromatograph), and instrumentation to monitor the reaction in real time (e.g., mass spectrometer). Here, we apply the TPRxn methodology to study molybdenum carbide catalysts for the deoxygenation of acetic acid, an important reaction among many in the upgrading/stabilization of biomass pyrolysis vapors. TPRxn is used to evaluate catalyst activity and selectivity and to test hypothetical reaction pathways (e.g., decarbonylation, ketonization, and hydrogenation). Furthermore, the results of the TPRxn study of acetic acid deoxygenation show that molybdenum carbide is an active catalyst for this reaction at temperatures above ca. 300 °C and that the reaction favors deoxygenation (i.e., C-O bond-breaking) products at temperatures below ca. 400 °C and decarbonylation (i.e., C-C bond-breaking) products at temperatures above ca. 400 °C.},
doi = {10.3791/55314},
journal = {Journal of Visualized Experiments},
number = 120,
volume = 2017,
place = {United States},
year = {Tue Feb 07 00:00:00 EST 2017},
month = {Tue Feb 07 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
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Cited by: 1work
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  • Ex situ catalytic fast pyrolysis (CFP) is a promising route for producing fungible biofuels; however, this process requires bifunctional catalysts that favor C–O bond cleavage, activate hydrogen at near atmospheric pressure and high temperature (350–500 °C), and are stable under high-steam, low hydrogen-to-carbon environments. Recently, early transition-metal carbides have been reported to selectively cleave C–O bonds of alcohols, aldehydes, and oxygenated aromatics, yet there is limited understanding of the metal carbide surface chemistry under reaction conditions and the identity of the active sites for deoxygenation. In this study, we evaluated molybdenum carbide (Mo 2C) for the deoxygenation of acetic acid,more » an abundant component of biomass pyrolysis vapors, under ex situ CFP conditions, and we probed the Mo 2C surface chemistry, identity of the active sites, and deoxygenation pathways using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations.« less
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