Theoretical investigations of the structures and properties of molybdenum-based sulfide catalysts

Sun, Mingyong; Adjaye, John; Nelson, Alan E.

doi:10.1016/j.apcata.2003.12.011

Cited by 159 publications

(106 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They found that the most likely products of CO hydrogenation are CH 4 and CO 2 , in agreement with the experiment results [8]. However, according to the studies of Travert et al [32], Cristol et al [29,34], Raybaud et al [33], and Sun et al [28,36], the two terminations considered by Huang and Cho [35] do not seem to reflect the realistic catalyst. They are not stable for H 2 S/H 2 pressure ratios in the range 0.0001 < p(H 2 S)/p(H 2 ) < 10000 [34].…”

Section: Introductionsupporting

confidence: 76%

“…They are not stable for H 2 S/H 2 pressure ratios in the range 0.0001 < p(H 2 S)/p(H 2 ) < 10000 [34]. For p(H 2 S)/p(H 2 ) < 0.05 corresponding to the realistic catalytic system the MoS 2 (10-10) surface is terminated by Mo metal sheets covered with about 50% sulfur and by S sheets with about 4 50% sulfur vacancies [28,29,[32][33][34]36] as mentioned above. These terminations have been considered in the present work.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

CO hydrogenation reaction on sulfided molybdenum catalysts

Shi

Jiao

Hermann

et al. 2009

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

Adsorption of reaction intermediates appearing during CO hydrogenation at the sulfur covered MoS 2 (10-10) surfaces, Mo-termination with 42% S coverage and S-termination with 50% S coverage, are investigated systematically using periodic density functional theory methods. Computed vibrational frequencies of all intermediates are compared with observed data from infrared (IR) spectroscopy allowing a detailed interpretation and assignment of the different features in the experimental spectra. The pathway for CO hydrogenation on both terminations has been studied in detail where the most likely reaction path involves C 1 type surface species in the sequence in agreement with experiment.

show abstract

Section: Introductionsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

CO hydrogenation reaction on sulfided molybdenum catalysts

Shi

Jiao

Hermann

et al. 2009

Journal of Molecular Catalysis A: Chemical

View full text Add to dashboard Cite

show abstract

“…5,6 The adsorption geometry and bonding mode of organic molecules on the MoS 2 -catalyst edge surfaces are also not totally understood. 7 Therefore, new theoretical work can lead to increased understanding of the relationships between activity and structure of hydrotreatment catalysis, especially at the atomic level.…”

Section: Introductionmentioning

confidence: 99%

“…5,22 There are recent reviews on the subject. 7,23,24 Results from scanning-tunneling-microscopy (STM) experiments 25,26 and systematic DFT calculations 24,27 suggest the decoration or Co-Mo-S model as the most probable model of substituted MoS 2 catalysts. In this model, Co or Ni promoter atoms substitute Mo atoms in the edge planes.…”

mentioning

confidence: 99%

Probing topological electronic effects in catalysis: thiophene adsorption on NiMoS and CoMoS clusters

Borges¹,

Silva²

2012

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Um método teórico geral em duas etapas para estudar redistribuições eletrônicas em processos catalíticos é apresentado. Na primeira etapa, teoria do funcional da densidade (DFT) é usada para otimizar completamente duas geometrias: o aglomerado que representa o catalisador e o sistema aglomerado mais molécula adsorvida. Na segunda etapa, a densidade eletrônica molecular convergida é dividida em multipolos centrados em sítios atômicos obtidos segundo uma análise de multipolos distribuídos, que fornece informação topológica detalhada da redistribuição de carga do catalisador e da molécula, antes e depois da adsorção. Esta abordagem é aplicada para a adsorção de tiofeno sobre a borda metálica 10 -10 dos catalisadores Ni(Co)MoS e comparada com a mesma reação em MoS 2 não-substituído. Energias de adsorção, geometrias e a análise de multipolos calculada indicam uma fraca adsorção do tiofeno em ambas as situações. Um modelo coulombiano para a ligação química mostra que a magnitude da ligação metal-enxofre na superfície dos catalisadores de Ni(Co)MoS promovidos é consideravelmente menor do que em MoS 2 não substituído, desta forma confirmando a origem do aumento da atividade de hidrodessulfurização (HDS) nestes catalisadores.A general two-step theoretical approach to study electronic redistributions in catalytic processes is presented. In the first step, density functional theory (DFT) is used to fully optimize two geometries: the cluster representing the catalyst and the cluster plus adsorbed molecule system. In the second step, the converged electron density is divided into multipoles centered on atomic sites according to a distributed multipole analysis which provides detailed topological information on the charge redistribution of catalyst and molecule before and after adsorption. This approach is applied to thiophene adsorption on the 10 -10 metal edge of Ni(Co)MoS catalysts and compared to the same reaction on bare MoS 2 . Calculated adsorption energies, geometries and multipole analysis indicate weak thiophene chemisorption on both cases. A Coulombic bond model showed that surface metal-sulfur bond strengths in Ni(Co)MoS promoted catalysts are considerably smaller than in bare MoS 2 , thus confirming the origin of the enhancement of hydrodesulfurization (HDS) activity in these catalysts.

show abstract

“…5 Molybdenum disulfide (MoS 2 ), which belongs to the family of transition-metal dichalcogenides (TMDs), has been receiving some research attention as a viable energy storage materials, both as supercapacitor and anode material for lithium-ion batteries. 6,7 As an important inorganic layered materials, MoS 2 has been shown to be an analogue of graphene, 8 and useful as hydrogen storage, 9 catalysis, 10 supercapacitors, 11 pseudocapacitors 12 and anode material for lithiumion batteries. 13 One of the active research areas of MoS 2 is in the fabrication of supercapacitors.…”

mentioning

confidence: 99%

The Effects of Morphology Re-Arrangements on the Pseudocapacitive Properties of Mesoporous Molybdenum Disulfide (MoS₂) Nanoflakes

Khawula

Raju

Franklyn

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

Mesoporous molybdenum disulfide (MoS 2 ) with different morphologies have been prepared via hydrothermal method using different solvents, water or water/acetone mixture. The MoS 2 obtained with water alone gave a graphene-like nanoflakes (g-MoS 2 ) while the other with water/acetone (1:1 ratio) gave a hollow-like morphology (h-MoS 2 ). Both materials are modified with carbon nanospheres as conductive material and investigated as symmetric pseudocapacitors in aqueous electrolyte (1 M Na 2 SO 4 solution). The physicochemical properties of the MoS 2 layered materials have been interrogated using the surface area analysis (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman, fourier-transform infrared (FTIR) spectroscopy, and advanced electrochemistry including cyclic voltammetry (CV), galvanostatic cycling with potential limitation (GCPL), repetitive electrochemical cycling tests, and electrochemical impedance spectroscopy (EIS). Interestingly, a simple change of synthesis solvents confers on the MoS 2 materials different morphologies, surface areas, and structural parameters, correlated by electrochemical capacitive properties. The g-MoS 2 exhibits higher surface area, higher capacitance parameters (specific capacitance of 183 F g −1 , maximum energy density of 9.2 Wh kg −1 and power density of 2.9 kW kg −1 ) but less stable electrochemical cycling compared to the h-MoS 2 . The findings show promises for the ability to tune the morphology of MoS 2 materials for enhanced energy storage. One of the factors that determine the performance of any energy material, be it in catalysis, sensing, photochemistry or electric energy storage, is its morphology.1 This explains why different materials with different dimensions (zero-, one-, two-or threedimensional nanostructures) give different physico-chemical properties and applications.2 Morphology has effects on the surface area, kinetics and thermodynamic properties of the materials.3 For example, it is has been known that graphene and carbon nanotubes give different catalytic properties due to their morphologies. 4 Nanowires are known to enhance electron transport compared to nanoparticles of the same materials.

show abstract

Theoretical investigations of the structures and properties of molybdenum-based sulfide catalysts

Cited by 159 publications

References 51 publications

CO hydrogenation reaction on sulfided molybdenum catalysts

CO hydrogenation reaction on sulfided molybdenum catalysts

Probing topological electronic effects in catalysis: thiophene adsorption on NiMoS and CoMoS clusters

The Effects of Morphology Re-Arrangements on the Pseudocapacitive Properties of Mesoporous Molybdenum Disulfide (MoS₂) Nanoflakes

Contact Info

Product

Resources

About

Theoretical investigations of the structures and properties of molybdenum-based sulfide catalysts

Cited by 159 publications

References 51 publications

CO hydrogenation reaction on sulfided molybdenum catalysts

CO hydrogenation reaction on sulfided molybdenum catalysts

Probing topological electronic effects in catalysis: thiophene adsorption on NiMoS and CoMoS clusters

The Effects of Morphology Re-Arrangements on the Pseudocapacitive Properties of Mesoporous Molybdenum Disulfide (MoS2) Nanoflakes

Contact Info

Product

Resources

About

The Effects of Morphology Re-Arrangements on the Pseudocapacitive Properties of Mesoporous Molybdenum Disulfide (MoS₂) Nanoflakes