Operando QEXAFS studies of Ni<sub>2</sub>P during thiophene hydrodesulfurization: direct observation of Ni—S bond formation under reaction conditions

Wada, Takahiro; Bando, Kyoko K.; Miyamoto, Takeshi; Takakusagi, Satoru; Oyama, S. Ted; Asakura, Kiyotaka

doi:10.1107/s0909049512001197

Cited by 15 publications

(14 citation statements)

References 26 publications

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“…After the completion of Ni-S bond formation, the tetrahydrothiphene (reaction intermediate) and H 2 S (product) were suddenly observed, indicating the Ni-S bond created under the reaction conditions was involved in the catalytic cycles and was the real active structure [8][9][10][11].…”

Section: Exafs After Co Desorption Exafs With Adsorbed Comentioning

confidence: 99%

New Prospects for the Characterization of Heterogeneous Catalysts by Using Slow Muon Spectroscopy

Mauriello

Ariga

Murata

et al. 2014

Proceedings of the International Symposium on Science Explored by Ultra Slow Muon (USM2013)

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In this contribution we show two examples concerning catalyses to consider the possible applications of slow muon to characterize catalytic systems. One is a Pd/Fe 3 O 4 catalyst that can be used in the catalytic valorization of glycerol, a product from biomass. The other is Pt/SnO 2 for a CH 4 sensor application. We present the unsolved problems and stress the importance on the in situ characterization. We discuss the possibility of slow muon for the in situ characterization of oxide catalyst material.

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Section: Exafs After Co Desorption Exafs With Adsorbed Comentioning

confidence: 99%

New Prospects for the Characterization of Heterogeneous Catalysts by Using Slow Muon Spectroscopy

Mauriello

Ariga

Murata

et al. 2014

Proceedings of the International Symposium on Science Explored by Ultra Slow Muon (USM2013)

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“…Numerous excellent studies have resulted from experiments performed on the dispersive EXAFS beamline [141][142][143][144][145][146][147][148][149]. Now, with the synchrotron SOLEIL, the kinetics of chemical reaction can be followed on 2 beamlines, namely "SAMBA," with the "Quick Different major scientific breakthroughs have been achieved using of Quick EXAFS [156][157][158][159][160][161][162][163][164][165][166][167][168]. As underlined by R. Frahm [169], this new approach significantly reduces data collection time as compared with the classical step-by-step technique.…”

Section: Following the Chemical Reaction "In Real Time"mentioning

confidence: 99%

François Garin: Pioneer work in catalysis through synchrotron radiation

Bazin¹

2013

Comptes Rendus. Chimie

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Progress in the kinetics and mechanisms of chemical reactions at the atomic and molecular levels. Dedicated to the scientific work of François GarinInternational audienceStarting from the late seventies, the progressively increased availability of beamlines dedicated to X-ray absorption spectroscopy allowed the execution of experiments in chemistry. In this manuscript, I describe the contribution of François Garin at the frontier of heterogeneous catalysis and synchrotron radiation. Working at \LURE\ as a scientific in charge of a beamline dedicated to X-ray absorption spectroscopy during almost twenty years and thus, having the opportunity to discuss with research groups working in heterogeneous catalysis in Europe as well as in the United States, it was quite easy to show that his work is clearly at the origin of current research in heterogeneous catalysis, not only in France, but in different synchrotron radiation centres

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“…A definite decrease in intensity (marked by an arrow) was observed after the H 2 S treatment, which was quite similar to the change found during HDS reactions. 9 However, the bond lengths were different from each other. If the change occurred owing to the electronic modification of Ni or a multiple scattering effect, the changes in the 8333 eV feature should be different for the NiS bonds obtained from H 2 S and from thiophene during the HDS reaction.…”

Section: ¹1mentioning

confidence: 99%

Operando Observation of Ni2P Structural Changes during Catalytic Reaction: Effect of H2S Pretreatment

et al. 2012

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In situ X-ray absorption spectroscopy was used to study the effect of H 2 S pretreatment on the activation of Ni 2 P catalysts for the thiophene hydrodesulfurization (HDS) reaction. It was found that H 2 S treatment produced NiS bonds that were slightly longer and that had higher coordination numbers than those formed during reaction. The longer NiS bonds formed by H 2 S treatment were changed to the shorter NiS bonds by the catalytic reaction, and these shorter bonds were associated with high activity. The work provides evidence that a NiPS phase is active in the HDS reaction.Removal of sulfur compounds from petroleum feedstocks is important for satisfying environmental regulations. Nickel phosphide (Ni 2 P) catalysts have shown higher catalytic activity in hydrodesulfurization (HDS) reactions than commercially available NiMoS or CoMoS catalysts have.14 Previous work with time-resolved simultaneous measurements of quick X-ray absorption fine-structure (QXAFS) and Fourier transform infrared (FTIR) spectra of Ni 2 P catalysts during thiophene HDS indicated that a nickel phosphosulfide (NiPS) phase was responsible for the catalytic activity. 59 Recently, it was reported that pretreatment of Ni 2 P by H 2 S had a positive effect on the catalytic activity probably because of the formation of a surface NiPS phase.10,11 However, no information has been presented about the structure of the active catalyst formed by the H 2 S treatment. This paper reports results of in situ XAFS analysis of the Ni 2 P during the H 2 S pretreatment and the Ni 2 P after the HDS reaction with and without H 2 S treatment. The results indicate the formation of a catalytically active NiPS phase.The MCM-41-supported Ni 2 P catalysts of loading 1.15 mmol Ni g support ¹1 (12.2 wt % Ni 2 P/support) were prepared as described in previous reports. 6,8 Briefly, the support was impregnated with a solution of nickel nitrate and ammonium phosphate, dried, calcined, and reduced (See Supporting Information (SI)). 23 For the measurements in this study, 30.0 mg of reduced and then passivated samples was pressed into a disk with a diameter of 15 mm and was re-reduced in a XAFS cell under H 2 flow (100 mL min ¹1 ) at 803 K for 2 h (H 2 activated sample). The thus-reduced sample was first cooled to a set temperature (529, 559, and 583 K) to measure the in situ EXAFS and was then treated in 5.0 vol % H 2 S/H 2 at 559 K for 0.3 h until in situ XAFS monitoring of a NiS bond showed no changes. The sample was then cooled or heated again to the HDS reaction temperatures under He flow. The sample was not moved during these steps, which allowed the measurement of accurate difference spectra. The mixed reactant gas composed of thiophene (0.1 vol %), He (1.9 vol %), and H 2 (98 vol %) was introduced at a rate of 100 mL min 12 The ring energy and current were 2.5 GeV and 430 mA, respectively. The monochromator was rotated by a stepping motor at a speed at 10 s per spectrum in the Ni K-edge region from 8080 to 8900 eV. It took another 10 s to rewind the motor and save t...

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Operando QEXAFS studies of Ni₂P during thiophene hydrodesulfurization: direct observation of Ni—S bond formation under reaction conditions

Cited by 15 publications

References 26 publications

New Prospects for the Characterization of Heterogeneous Catalysts by Using Slow Muon Spectroscopy

New Prospects for the Characterization of Heterogeneous Catalysts by Using Slow Muon Spectroscopy

François Garin: Pioneer work in catalysis through synchrotron radiation

Operando Observation of Ni2P Structural Changes during Catalytic Reaction: Effect of H2S Pretreatment

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Operando QEXAFS studies of Ni2P during thiophene hydrodesulfurization: direct observation of Ni—S bond formation under reaction conditions

Cited by 15 publications

References 26 publications

New Prospects for the Characterization of Heterogeneous Catalysts by Using Slow Muon Spectroscopy

New Prospects for the Characterization of Heterogeneous Catalysts by Using Slow Muon Spectroscopy

François Garin: Pioneer work in catalysis through synchrotron radiation

Operando Observation of Ni2P Structural Changes during Catalytic Reaction: Effect of H2S Pretreatment

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Operando QEXAFS studies of Ni₂P during thiophene hydrodesulfurization: direct observation of Ni—S bond formation under reaction conditions