In-situ HRTEM study of the reactive carbide phase of Co/MoS2 catalyst

Ramos, Manuel; Ferrer, Domingo; Martinez-Soto, Eduan; Lopez-Lippmann, Hugo; Torres, Brenda; Berhault, Gilles; Chianelli, Russell R.

doi:10.1016/j.ultramic.2012.07.012

Cited by 19 publications

(16 citation statements)

References 27 publications

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“…The 2q of 30.096 and 44.683 corresponded to the planes (101) and (103) of the molybdenum silicide. This confirmed the formation of MoSi 2 in the spent catalyst which was in agreement with previous research [45] and (JCPDS: 41-0612). Thus, the molybdenum species in the spent catalyst were majorly composed of MoO 3 .…”

Section: Tgasupporting

confidence: 92%

Synthesis of gasoline-range hydrocarbons from nitrogen-rich syngas over a Mo/HZSM-5 bi-functional catalyst

Jin

Han

et al. 2016

Journal of the Energy Institute

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Keywords:Hydrocarbons Syngas Mo/HZSM-5 Bi-functional catalyst Coke deposition a b s t r a c tThe production of gasoline-range hydrocarbons from nitrogen-rich syngas was studied over a Mo/HZSM-5 bi-functional catalyst in a bench-scale continuous stainless steel fixed-bed reactor with different reaction conditions. The reaction conditions, i.e., temperature, pressure, and gas hourly space velocity (GHSV), significantly affected the hydrocarbon selectivity. Mo/HZSM-5 was more active in a temperature zone between 350 and 380 C, a reaction pressure of 1000 psig, and a GHSV of 600 h À1 within the test operation condition ranges that were used. More than 20 hydrocarbons were mainly identified from the oil phase sample and can be classified as iso-paraffin, aromatic and naphthene hydrocarbons. The carbon number of the oil sample from the nitrogen-rich syngas mainly contained C 8 eC 10 hydrocarbons. A high content of nitrogen in syngas was found to have an effect on the liquid hydrocarbon distribution over the Mo/HZSM-5 catalyst.

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Section: Tgasupporting

confidence: 92%

Synthesis of gasoline-range hydrocarbons from nitrogen-rich syngas over a Mo/HZSM-5 bi-functional catalyst

Jin

Han

et al. 2016

Journal of the Energy Institute

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“…and Casillas et al . These authors showed carburization effects on fresh MoS 2 and MoS 2 /Co catalysts 20 , crystal formation from molybdenum oxide precursors in the presence of H 2 S and H 2 as well as variations of micromechanical properties 21 , 22 . In other works, STEM 3D tomography was used, as reported by P.A Midgley and R.E.…”

Section: Introductionmentioning

confidence: 99%

Electron tomography and fractal aspects of MoS2 and MoS2/Co spheres

Ramos¹,

Galindo-Hernández²,

Arslan

et al. 2017

Sci Rep

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A study was made by a combination of 3D electron tomography reconstruction methods and N2 adsorption for determining the fractal dimension for nanometric MoS2 and MoS2/Co catalyst particles. DFT methods including Neimarke-Kiselev’s method allowed to determine the particle porosity and fractal arrays at the atomic scale for the S-Mo-S(Co) 2D- layers that conform the spherically shaped catalyst particles. A structural and textural correlation was sought by further characterization performed by x-ray Rietveld refinement and Radial Distribution Function (RDF) methods, electron density maps, computational density functional theory methods and nitrogen adsorption methods altogether, for studying the structural and textural features of spherical MoS2 and MoS2/Co particles. Neimark-Kiselev’s equations afforded the evaluation of a pore volume variation from 10 to 110 cm3/g by cobalt insertion in the MoS2 crystallographic lattice, which induces the formation of cavities and throats in between of less than 29 nm, with a curvature radius r k < 14.4 nm; typical large needle-like arrays having 20 2D layers units correspond to a model consisting of smooth surfaces within these cavities. Decreasing D P, D B, D I and D M values occur when Co atoms are present in the MoS2 laminates, which promote the formation of smoother edges and denser surfaces that have an influence on the catalytic properties of the S-Mo-S(Co) system.

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“…High-resolution transmission electron microscopy (HRTEM) combined with selected area electron diffraction (SAED) is also a promising technique that can determine the morphology and provide detailed information on organo-mineral surfaces, as well as changes in their surface chemistries (Wen et al, 2014a;Yaron-Marcovich et al, 2005). Although direct observations of organo-mineral complexes by NanoSIMS and HRTEM have been previously described (Ramos et al, 2013;Vogel et al, 2014;Rumpel et al, 2015), few studies have reported the effects of fertilization practices on the organo-mineral complexes in soil colloids. In addition, X-ray photoelectron spectroscopy (XPS) can identify the oxidation state of elements on the surface (2-10 nm) of minerals (Zhu et al, 2014).…”

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confidence: 99%

New strategies for submicron characterization the carbon binding of reactive minerals in long-term contrasting fertilized soils: implications for soil carbon storage

Xiao¹,

He²,

Hao³

et al. 2016

Biogeosciences

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Mineral binding is a major mechanism for soil carbon (C) stabilization. However, the submicron information about the in situ mechanisms of different fertilization practices affecting organo-mineral complexes and associated C preservation remains unclear. Here, we applied nano-scale secondary ion mass spectrometry (NanoSIMS), X-ray photoelectron spectroscopy (XPS), and X-ray absorption fine structure spectroscopy (XAFS) to examine differentiating effects of inorganic versus organic fertilization on interactions between highly reactive minerals and soil C preservation. To examine such interactions, soils and their extracted colloids were collected during a 24-year longterm fertilization period (1990-2014) (no fertilization, control; chemical nitrogen (N), phosphorus (P), and potassium (K) fertilization, NPK; and NPK plus swine manure fertilization, NPKM). The results for different fertilization conditions showed a ranked soil organic matter concentration with NPKM > NPK > control. Meanwhile, oxalateextracted Al (Al o ), Fe (Fe o ), short-range ordered Al (Al xps ), Fe (Fe xps ), and dissolved organic carbon (DOC) ranked with NPKM > control > NPK, but the ratios of DOC / Al xps and DOC / Fe xps ranked with NPKM > NPK > control. Compared with the NPK treatment, the NPKM treatment enhanced the C-binding loadings of Al and Fe minerals in soil colloids at the submicron scale. Furthermore, a greater concentration of highly reactive Al and Fe minerals was presented under NPKM than under NPK. Together, these submicron-scale findings suggest that both the reactive mineral species and their associations with C are differentially affected by 24-year long-term inorganic and organic fertilization.

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In-situ HRTEM study of the reactive carbide phase of Co/MoS2 catalyst

Cited by 19 publications

References 27 publications

Synthesis of gasoline-range hydrocarbons from nitrogen-rich syngas over a Mo/HZSM-5 bi-functional catalyst

Synthesis of gasoline-range hydrocarbons from nitrogen-rich syngas over a Mo/HZSM-5 bi-functional catalyst

Electron tomography and fractal aspects of MoS2 and MoS2/Co spheres

New strategies for submicron characterization the carbon binding of reactive minerals in long-term contrasting fertilized soils: implications for soil carbon storage

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