Title: Highly Active Ceria-Supported Ru Catalyst for the Dry Reforming of Methane: In Situ Identification of Ru^δ+ –Ce³⁺ Interactions for Enhanced Conversion

Abstract

The metal-oxide interaction changes the surface electronic states of catalysts deployed for chemical conversion, yet details of its influence on the catalytic performance under reaction conditions remain obscure. In this work, we report the high activity/stability of a ceria supported Ru-nanocluster (<1nm) catalyst during the dry reforming of methane. To elucidate the structure-reactivity relationship underlying the catalyst’s remarkable catalytic performance, the active structure and chemical speciation of the catalyst was characterized using in-situ X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS), while the surface chemistry and active intermediates were monitored by in-situ ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Methane activates on the catalyst surface at temperatures as low as 150 °C. Under reaction conditions, the existence of metal-support interactions tunes the electronic properties of the Ru nanoclusters, giving rise to a partially oxidized state of ruthenium stabilized by reduced ceria (Ru^δ+-CeO_2-x) to sustain active chemistry, which is found to be very different from that of large Ru nanoparticles supported on ceria. The oxidation of surface carbon is also a crucial step for the completion of the catalytic cycle, and this is strongly correlated with the oxygen transfer governed by the Ru^δ+-CeO_2-x interactionsmore » at higher temperatures (> 300 °C). The possible reaction pathways and stable surface intermediates were identified using DRIFTS including ruthenium carbonyls, carboxylate species, and surface -OH groups while polydentate carbonates may be plain spectators at the measured reaction conditions.« less

Authors:

Liu, Zongyuan  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-8526-5590"

Zhang, Feng ^[2]; Rui, Ning ^[1]; Li, Xing ^[3]; Lin, Lili ^[1]; Betancourt, Luis E. ^[1]; Su, Dong  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-1921-6683"

Xu, Wenqian ^[4]; Cen, Jiajie  ^[2];

• Search DOE PAGES for author "Cen, Jiajie"
• Search DOE PAGES for ORCID "0000-0002-9446-5161"

Attenkofer, Klaus ^[1]; Idriss, Hicham ^[5]; Rodriguez, José A.  ^[6];

• Search DOE PAGES for author "Rodriguez, José A."
• Search DOE PAGES for ORCID "0000-0002-5680-4214"

Senanayake, Sanjaya D.  ^[1]

• Search DOE PAGES for author "Senanayake, Sanjaya D."
• Search DOE PAGES for ORCID "0000-0003-3991-4232"

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+ Show Author Affiliations

1. Brookhaven National Lab. (BNL), Upton, NY (United States)
2. Stony Brook Univ., Stony Brook, NY (United States)
3. Brookhaven National Lab. (BNL), Upton, NY (United States); Zhengzhou Univ., Henan (China)
4. Argonne National Lab. (ANL), Argonne, IL (United States)
5. King Abdullah Univ. of Science and Technology (KAUST), Jeddah (Saudi Arabia)
6. Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States)

Publication Date:

Mon Mar 04 00:00:00 EST 2019

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:

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

OSTI Identifier:

1524089

Alternate Identifier(s):

OSTI ID: 1557112

Report Number(s):

BNL-211970-2019-JAAM
Journal ID: ISSN 2155-5435; 152729

Grant/Contract Number:  

AC02-06CH11357; SC0012704

Resource Type:

Accepted Manuscript

Journal Name:

ACS Catalysis

Additional Journal Information:

Journal Volume: 9; Journal Issue: 4; Journal ID: ISSN 2155-5435

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

AP-XPS; DRIFTS; EXAFS; XRD; ceria; methane dry reforming; ruthenium; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; dry reforming of methane