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:

Latimer, Allegra A.  ^[1];

• Search DOE PAGES for author "Latimer, Allegra A."
• Search DOE PAGES for ORCID "0000-0003-3048-6593"

Aljama, Hassan ^[1]; Kakekhani, Arvin ^[1]; Yoo, Jong Suk ^[1]; Kulkarni, Ambarish ^[1]; Tsai, Charlie ^[1]; Garcia-Melchor, Max  ^[1];

• Search DOE PAGES for author "Garcia-Melchor, Max"
• Search DOE PAGES for ORCID "0000-0003-1348-4692"

Abild-Pedersen, Frank ^[2]; Nørskov, Jens K. ^[2]

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+ Show Author Affiliations

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:

Wed Jan 11 00:00:00 EST 2017

Research Org.:

SLAC National Accelerator Lab., Menlo Park, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1349285

Grant/Contract Number:  

AC02-76SF00515

Resource Type:

Accepted Manuscript

Journal Name:

Physical Chemistry Chemical Physics. PCCP

Additional Journal Information:

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