Visualizing hydrogen-induced reshaping and edge activation in MoS₂ and Co-promoted MoS₂ catalyst clusters

TY - JOUR

T1 - Visualizing hydrogen-induced reshaping and edge activation in MoS2 and Co-promoted MoS2 catalyst clusters

AU - Gronborg, Signe S.

AU - Salazar, Norberto

AU - Bruix, Albert

AU - Rodriguez-Fernandez, Jonathan

AU - Thomsen, Sean D.

AU - Hammer, Bjork

AU - Lauritsen, Jeppe V.

PY - 2018/12/1

Y1 - 2018/12/1

N2 - Hydrodesulfurization catalysis ensures upgrading and purification of fossil fuels to comply with increasingly strict regulations on S emissions. The future shift toward more diverse and lower-quality crude oil supplies, high in S content, requires attention to improvements of the complex sulfided CoMo catalyst based on a fundamental understanding of its working principles. In this study, we use scanning tunneling microscopy to directly visualize and quantify how reducing conditions transforms both cluster shapes and edge terminations in MoS2 and promoted CoMoS-type hydrodesulfurization catalysts. The reduced catalyst clusters are shown to be terminated with a fractional coverage of sulfur, representative of the catalyst in its active state. By adsorption of a proton-accepting molecular marker, we can furthermore directly evidence the presence of catalytically relevant S-H groups on the Co-promoted edge. The experimentally observed cluster structure is predicted by theory to be identical to the structure present under catalytic working conditions.

AB - Hydrodesulfurization catalysis ensures upgrading and purification of fossil fuels to comply with increasingly strict regulations on S emissions. The future shift toward more diverse and lower-quality crude oil supplies, high in S content, requires attention to improvements of the complex sulfided CoMo catalyst based on a fundamental understanding of its working principles. In this study, we use scanning tunneling microscopy to directly visualize and quantify how reducing conditions transforms both cluster shapes and edge terminations in MoS2 and promoted CoMoS-type hydrodesulfurization catalysts. The reduced catalyst clusters are shown to be terminated with a fractional coverage of sulfur, representative of the catalyst in its active state. By adsorption of a proton-accepting molecular marker, we can furthermore directly evidence the presence of catalytically relevant S-H groups on the Co-promoted edge. The experimentally observed cluster structure is predicted by theory to be identical to the structure present under catalytic working conditions.

KW - ATOMIC-SCALE STRUCTURE

KW - SINGLE-LAYER MOS2

KW - HYDROTREATING CATALYSTS

KW - HYDRODESULFURIZATION CATALYSTS

KW - ELECTRONIC-STRUCTURE

KW - NANOCLUSTERS

KW - MORPHOLOGY

KW - DFT

KW - NANOPARTICLES

KW - SITES

UR - http://www.scopus.com/inward/record.url?scp=85048244320&partnerID=8YFLogxK

U2 - 10.1038/s41467-018-04615-9

DO - 10.1038/s41467-018-04615-9

M3 - Journal article

C2 - 29880841

SN - 2041-1723

VL - 9

JO - Nature Communications

JF - Nature Communications

IS - 1

M1 - 2211

ER -