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Title: Mechanistic insights into heterogeneous methane activation

Abstract

While natural gas is an abundant chemical fuel, its low volumetric energy density has prompted a search for catalysts able to transform methane into more useful chemicals. This search has often been aided through the use of transition state (TS) scaling relationships, which estimate methane activation TS energies as a linear function of a more easily calculated descriptor, such as final state energy, thus avoiding tedious TS energy calculations. It has been shown that methane can be activated via a radical or surface-stabilized pathway, both of which possess a unique TS scaling relationship. Herein, we present a simple model to aid in the prediction of methane activation barriers on heterogeneous catalysts. Analogous to the universal radical TS scaling relationship introduced in a previous publication, we show that a universal TS scaling relationship that transcends catalysts classes also seems to exist for surface-stabilized methane activation if the relevant final state energy is used. We demonstrate that this scaling relationship holds for several reducible and irreducible oxides, promoted metals, and sulfides. By combining the universal scaling relationships for both radical and surface-stabilized methane activation pathways, we show that catalyst reactivity must be considered in addition to catalyst geometry to obtain an accuratemore » estimation for the TS energy. Here, this model can yield fast and accurate predictions of methane activation barriers on a wide range of catalysts, thus accelerating the discovery of more active catalysts for methane conversion.« less

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1];  [1]; ORCiD logo [1];  [2];  [2]
  1. Stanford Univ., Stanford, CA (United States)
  2. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1349285
Grant/Contract Number:
AC02-76SF00515
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Chemistry Chemical Physics. PCCP (Print)
Additional Journal Information:
Journal Name: Physical Chemistry Chemical Physics. PCCP (Print); Journal Volume: 19; Journal Issue: 5; Journal ID: ISSN 1463-9076
Publisher:
Royal Society of Chemistry
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Latimer, Allegra A., Aljama, Hassan, Kakekhani, Arvin, Yoo, Jong Suk, Kulkarni, Ambarish, Tsai, Charlie, Garcia-Melchor, Max, Abild-Pedersen, Frank, and Nørskov, Jens K. Mechanistic insights into heterogeneous methane activation. United States: N. p., 2017. Web. doi:10.1039/C6CP08003K.
Latimer, Allegra A., Aljama, Hassan, Kakekhani, Arvin, Yoo, Jong Suk, Kulkarni, Ambarish, Tsai, Charlie, Garcia-Melchor, Max, Abild-Pedersen, Frank, & Nørskov, Jens K. Mechanistic insights into heterogeneous methane activation. United States. doi:10.1039/C6CP08003K.
Latimer, Allegra A., Aljama, Hassan, Kakekhani, Arvin, Yoo, Jong Suk, Kulkarni, Ambarish, Tsai, Charlie, Garcia-Melchor, Max, Abild-Pedersen, Frank, and Nørskov, Jens K. Wed . "Mechanistic insights into heterogeneous methane activation". United States. doi:10.1039/C6CP08003K. https://www.osti.gov/servlets/purl/1349285.
@article{osti_1349285,
title = {Mechanistic insights into heterogeneous methane activation},
author = {Latimer, Allegra A. and Aljama, Hassan and Kakekhani, Arvin and Yoo, Jong Suk and Kulkarni, Ambarish and Tsai, Charlie and Garcia-Melchor, Max and Abild-Pedersen, Frank and Nørskov, Jens K.},
abstractNote = {While natural gas is an abundant chemical fuel, its low volumetric energy density has prompted a search for catalysts able to transform methane into more useful chemicals. This search has often been aided through the use of transition state (TS) scaling relationships, which estimate methane activation TS energies as a linear function of a more easily calculated descriptor, such as final state energy, thus avoiding tedious TS energy calculations. It has been shown that methane can be activated via a radical or surface-stabilized pathway, both of which possess a unique TS scaling relationship. Herein, we present a simple model to aid in the prediction of methane activation barriers on heterogeneous catalysts. Analogous to the universal radical TS scaling relationship introduced in a previous publication, we show that a universal TS scaling relationship that transcends catalysts classes also seems to exist for surface-stabilized methane activation if the relevant final state energy is used. We demonstrate that this scaling relationship holds for several reducible and irreducible oxides, promoted metals, and sulfides. By combining the universal scaling relationships for both radical and surface-stabilized methane activation pathways, we show that catalyst reactivity must be considered in addition to catalyst geometry to obtain an accurate estimation for the TS energy. Here, this model can yield fast and accurate predictions of methane activation barriers on a wide range of catalysts, thus accelerating the discovery of more active catalysts for methane conversion.},
doi = {10.1039/C6CP08003K},
journal = {Physical Chemistry Chemical Physics. PCCP (Print)},
number = 5,
volume = 19,
place = {United States},
year = {Wed Jan 11 00:00:00 EST 2017},
month = {Wed Jan 11 00:00:00 EST 2017}
}

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