Hydrodeoxygenation of guaiacol

Bui, Van Ngoc; Laurenti, D.; Delichère, P.; Geantet, Christophe

doi:10.1016/j.apcatb.2010.10.031

Cited by 364 publications

(167 citation statements)

References 32 publications

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“…3c), the first two peaks located at 161.4 and 162.5 eV were due to the spin−orbit coupling in metal sulfide, 53, 54 while S 2p peak at 163.5 eV suggested the existence of covalent S-C bonds in the as-synthesized composites 55,56 indicating that S has been covalently inserted in N-doped porous carbon. 43 No peaks at around 164.5 eV corresponds to polysulfides (S n 2-) can be found in all samples, [57][58][59] and the peaks at 168.5 and 169.5 eV in S 2p spectrum indicate that inconsequential amount of Co x S y compounds were also formed during the thermal treatment process. 60,61 Moreover, the main peaks for N 1s spectra (shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Cobalt sulfide/N,S codoped porous carbon core–shell nanocomposites as superior bifunctional electrocatalysts for oxygen reduction and evolution reactions

et al. 2015

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Exploring highly-efficient and low-cost bifunctional electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reactions (OER) in the renewable energy area has gained its momentum but still remains a significant challenge. Here we represent a simple but efficient way that utilizes ZIF-67 as the precursor and template for the one-step generation of homogeneous dispersed cobalt sulfide/N,S-codoped porous carbon nanocomposites as high-performance electrocatalysts. Due to the favourable molecular-like structural features and uniform dispersed active sites in the precursor, the resulting nanocomposites featured with unique core-shell structure, high porosity, homogeneous dispersion active components together with N and S-doping effect, not only show excellent electrocatalytic activity towards ORR with the high onset potential (around -0.04 V vs -0.02 V for benchmark Pt/C catalyst) and four-electron pathway, and OER with a small overpotential of 0.47 V for 10 mA cm −2 current density, but also exhibit superior stability (92%) to commercial Pt/C catalyst (74%) in ORR and promising OER stability (80%) with good methanol tolerance. Our findings suggest that the transition metal sulfide-porous carbon nanocomposites derived from the one-step simultaneously sulfurization and carbonization of zeolitic imidazolate frameworks are excellent alternative bifuncitonal electrocatalysts towards ORR and OER in the next generation of energy storage and conversion technologies.With the depletion of hydrocarbon-based energy resources and the increasing global energy demands, it is imperative to develop green and sustainable energy storage and conversion technologies as alternatives to currently widely used fossil fuels. 1-3 Electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play key roles in several important next-generation energy storage and conversion technologies, such as fuel cells, metal-air batteries and water splitting. [4][5][6][7][8][9][10][11][12][13] Hitherto, most efficient electrocatalysts for ORR/OER contain precious metals including Pt or Ir; however, due to the prohibitive cost, poor stability of precious metals, the sluggish kinetics for ORR and the large polarisation, it is highly desirable to discover highly efficient and low-cost earthabundant non-precious electroactive materials that can rival the performances of precious metal-based catalysts. 14-17Many efforts have, therefore, been devoted to transition metal oxides/sulfides based materials, as many transition metals like cobalt, manganese have been widely considered to be electrochemical active for ORR and OER. Particularly, cobalt sulfides (Co x S y ) with different phases have been previously investigated as ORR and OER electrode catalysts and exhibited attractive electrocatalytic performance among different nonprecious and late transition metal chalcogenides.18 Co 9 S 8 is a good catalyst for ORR. 21 However, the complicated preparation procedures coupled with the low electrical conductivities of cobalt s...

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Section: Resultsmentioning

confidence: 99%

Cobalt sulfide/N,S codoped porous carbon core–shell nanocomposites as superior bifunctional electrocatalysts for oxygen reduction and evolution reactions

et al. 2015

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“…Ni-MoS2/ZrO2 was chosen as catalyst, as promotion by nickel previously has been shown to be slightly superior to cobalt promotion for HDO purposes [9,25] and ZrO2 was previously found as a suitable support for HDO [31][32][33][34][35] and does apparently not suffer from the instability in high concentration of water, as reported for the conventionally used -Al2O3 support for hydrotreating catalysts [9,36,37].…”

Section: Introductionmentioning

confidence: 99%

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

Mortensen

Gardini

Damsgaard

et al. 2016

Applied Catalysis A: General

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Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol, Applied Catalysis A, General http://dx.doi.org/10. 1016/j.apcata.2016.06.002 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Graphical abstractHighlights  Impurities as Cl, S, and K found in bio-oil will deactivate or inhibit MoS2-type catalyst by competing for the active sites  MoS2-based catalysts will produce sulfur containing hydrocarbons during HDO, but these can be removed again if a sufficiently high residence time is used enabling desulfurization of the product  Chlorine binds more strongly to the active sites of MoS2 based catalysts compared to H2O and H2S, while K irreversibly deactivates the catalyst 3 AbstractThe stability of Ni-MoS2/ZrO2 toward water, potassium, and chlorine containing compounds during hydrodeoxygenation (HDO) of a mixture of phenol and 1-octanol was investigated in a high pressure gas and liquid continuous flow fixed bed setup at 280°C and 100 bar. To maintain the stability of the catalyst, sufficient co-feeding of a sulfur source was necessary to avoid oxidation of the sulfide phase by oxygen replacement of the edge sulfur atoms in the MoS2 structure. However, the addition of sulfur to the feed gas resulted in the formation of sulfur containing compounds, mainly thiols, in the oil product if the residence time was too low. At a weight hourly space velocity (WHSV) of 4.9 h -1 the sulfur content in the liquid product was 980 ppm by weight, but this could be decreased to 5 ppm at a WHSV of 1.4 h -1 . A high co-feed of sulfur was needed when water was present in the feed and the H2O/H2S molar ratio should be below ca. 10 to maintain a decent stability of the catalyst. Chlorine containing compounds caused a reversible deactivation of the catalyst when co-fed to the reactor, where the catalytic activity could be completely regained when removing it from the feed. Commonly, chlorine, H2O, and H2S all inhibited the activity of the catalyst by competing for the active sites, with chlorine being by far the strongest inhibitor and H2S and H2O of roughly the same strength. Dissimilar, potassium was a severe poison and irreversibly deactivated the catalyst to <5% degree of deoxygenation when impregnated on the catalyst in a stoichiometric ratio relative to the active metal. This deactivation was a result of adsorption of potassium on the edge vacancy sites of the MoS2 slabs.

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“…In addition to reactant structures, catalyst properties such as acidity play an important role in coke formation. In the study for HDO of guaiacol over CoMoS catalysts, Bui et al reported the conventional alumina support obviously induced the formation of heavier products resulting in catalyst deactivation, while supports with less acidity (ZrO 2 and TiO 2 ) formed less heavy by-products [116]. Meanwhile, it is proposed that Lewis acid sites bind reactant species adsorb to catalyst surface, and Brønsted acid sites supply protons to form carbocations as coke precursors [114].…”

Section: Catalyst Deactivationmentioning

confidence: 99%

An Overview on Catalytic Hydrodeoxygenation of Pyrolysis Oil and Its Model Compounds

et al. 2017

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Abstract:Pyrolysis is considered the most promising way to convert biomass to fuels. Upgrading biomass pyrolysis oil is essential to produce high quality hydrocarbon fuels. Upgrading technologies have been developed for decades, and this review focuses on the hydrodeoxygenation (HDO). In order to declare the need for upgrading, properties of pyrolysis oil are firstly analyzed, and potential analysis methods including some novel methods are proposed. The high oxygen content of bio-oil leads to its undesirable properties, such as chemical instability and a strong tendency to re-polymerize. Acidity, low heating value, high viscosity and water content are not conductive to making bio-oils useful as fuels. Therefore, fast pyrolysis oils should be refined before producing deoxygenated products. After the analysis of pyrolysis oil, the HDO process is reviewed in detail. The HDO of model compounds including phenolics monomers, dimers, furans, carboxylic acids and carbohydrates is summarized to obtain sufficient information in understanding HDO reaction networks and mechanisms. Meanwhile, investigations of model compounds also make sense for screening and designing HDO catalysts. Then, we review the HDO of actual pyrolysis oil with different methods including two-stage treatment, co-feeding solvents and in-situ hydrogenation. The relative merits of each method are also expounded. Finally, HDO catalysts are reviewed in order of time. After the summarization of petroleum derived sulfured catalysts and noble metal catalysts, transitional metal carbide, nitride and phosphide materials are summarized as the new trend for their low cost and high stability. After major progress is reviewed, main problems are summarized and possible solutions are raised.

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Hydrodeoxygenation of guaiacol

Cited by 364 publications

References 32 publications

Cobalt sulfide/N,S codoped porous carbon core–shell nanocomposites as superior bifunctional electrocatalysts for oxygen reduction and evolution reactions

Cobalt sulfide/N,S codoped porous carbon core–shell nanocomposites as superior bifunctional electrocatalysts for oxygen reduction and evolution reactions

Deactivation of Ni-MoS2 by bio-oil impurities during hydrodeoxygenation of phenol and octanol

An Overview on Catalytic Hydrodeoxygenation of Pyrolysis Oil and Its Model Compounds

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