Title: In Situ Strong Metal–Support Interaction (SMSI) Affects Catalytic Alcohol Conversion

Abstract

Strong metal–support interactions (SMSIs) and catalyst deactivation have been heavily researched for decades by the catalysis community. The promotion of SMSIs in supported metal oxides is commonly associated with H₂ treatment at high temperature (>500 °C), and catalyst deactivation is commonly attributed to sintering, leaching of the active metal, and overoxidation of the metal, as well as strong adsorption of reaction intermediates. Alcohols can reduce metal oxides, and thus here we have hypothesized that catalytic conversion of alcohols can promote SMSIs in situ. In this work we show, via IR spectroscopy of CO adsorption and electron energy loss spectroscopy (EELS), that during 2-propanol conversion over Pd/TiO₂ coverage of Pd sites occurs due to SMSIs at low reaction temperatures (as low as ~ 190 °C). The emergence of SMSIs during the reaction (in situ) explains the apparent catalyst deactivation when the reaction temperature is varied. A steady-state isotopic transient kinetic analysis (SSITKA) shows that the intrinsic reactivity of the catalytic sites does not change with temperature when SMSI is promoted in situ; rather, the number of available active sites changes (when a TiO_x layer migrates over Pd NPs). SMSI generated during the reaction fully reverses upon exposure to O₂ at roommore » temperature for ~15 h, which may have made their identification elusive up to now.« less

Authors:

Polo-Garzon, Felipe  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-6507-6183"

Blum, Thomas F.  ^[2];

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• Search DOE PAGES for ORCID "0000-0001-5836-7444"

Bao, Zhenghong  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-4615-9741"

Wang, Kristen ^[3]; Fung, Victor  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-3347-6983"

Huang, Zhennan ^[2]; Bickel, Elizabeth E. ^[4]; Jiang, De-en  ^[3];

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• Search DOE PAGES for ORCID "0000-0001-5167-0731"

Chi, Miaofang  ^[2];

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• Search DOE PAGES for ORCID "0000-0003-0764-1567"

Wu, Zili  ^[5]

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• Search DOE PAGES for ORCID "0000-0002-4468-3240"

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
3. Univ. of California, Riverside, CA (United States)
4. Tennessee Technological Univ., Cookeville, TN (United States)
5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division and Center for Nanophase Materials Sciences (CNMS)

Publication Date:

Thu Jan 28 00:00:00 EST 2021

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division

OSTI Identifier:

1764451

Grant/Contract Number:  

AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

ACS Catalysis

Additional Journal Information:

Journal Volume: 11; Journal Issue: n/a; Journal ID: ISSN 2155-5435

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; strong metal−support interaction; alcohol conversion; supported-metal catalysts; acid−base catalysis; FTIR; EELS; SSITKA