591-49-1Relevant articles and documents
Role of hydrogenolysis and nucleophilic substitution in hydrodenitrogenation over sulfided NiMo/γ-Al2O3
Prins,Rota
, p. 195 - 199 (2001)
The HDS of cyclohexanethiol and 2-methylcyclohexanethiol was studied over a sulfided NiMO/γ-Al2O3 catalyst. About 66% of the thiols reacted by elimination to (methyl)cyclohexene and 33% by hydrogenolysis of the C-S bond to (methyl)cyclohexane. These values were slightly lower than those for the selectivity to methylcyclohexene and slightly higher than those for the selectivity to methylcyclohexane in the HDN of 2-methylcyclohexylamine. HDN occurred predominantly in aliphatic molecules that contained H atoms in the β position relative to the nitrogen atom by elimination of ammonia. Part of the remaining HDN occurred by nucleophilic substitution of the amine by H2S, followed by elimination of H2S from the resulting thiol and, to a lesser extent, by C-S bond hydrogenolysis, the rest of the remaining HDN occurred by direct hydrogenolysis of the C-N bond.
Influence of noble metals (Pd, Pt) on the performance of Ru/Al2O3 based catalysts for toluene hydrogenation in liquid phase
Suppino, Raphael Soeiro,Landers, Richard,Cobo, Antonio José Gomez
, p. 41 - 49 (2016)
Catalytic hydrogenation of aromatic compounds is of great interest due to environmental aspects and the wide range of industrial processes involving such reaction. In this context, the present work aims to study the influence of Pd or Pt addition on the performance of Ru/Al2O3 based catalysts for toluene hydrogenation in liquid phase. For this, catalysts were prepared by wet impregnation from chlorinated precursors and reduced in liquid phase by formaldehyde (H2CO). After impregnation, a part of the catalysts were activated ex situ at 573?K or in situ at 523?K under H2. The studied solids were characterized by N2 physisorption, SEM?+?EDX, TEM, XPS and TPR techniques. Catalytic tests were conducted in a slurry Parr reactor at 373?K under constant H2 pressure of 5?MPa. Results show that solids reduction by H2CO led to metallic species, while the activation treatments form oxides and decrease the catalytic activity. The initial reaction rate of non-activated monometallic catalysts follows the order: Ru/Al2O3???Pd/Al2O3?≈?Pt/Al2O3. A synergistic effect on the activity of Ru/Al2O3 based catalysts is induced by the Pt addition.
Kinetic investigation of the effect of nickel and fluorine on the HDN of methylcyclohexylamine over WS2/Al2O3 catalysts
Sun, Mingyong,Prins, Roel
, p. 138 - 144 (2001)
The effects of incorporation of nickel and fluorine in WS2/Al2O3 catalysts on the kinetics of the hydrodenitrogenation of methylcyclohexylamine were investigated. The catalysts were prepared from ammonium tetrathiotungstat
Electrocatalytic hydrogenation of toluene using a proton exchange membrane reactor: Influence of catalyst materials on product selectivity
Fukazawa, Atsushi,Takano, Ken,Matsumura, Yoshimasa,Nagasawa, Kensaku,Mitsushima, Shigenori,Atobe, Mahito
, p. 897 - 899 (2018)
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Hydrodeoxygenation of m-cresol as a depolymerized lignin probe molecule: Synergistic effect of NiCo supported alloys
Gon?alves, Vinicius Ottonio O.,Talon, Walter Henrique S.M.,Kartnaller, Vinicius,Venancio, Fabricio,Cajaiba, Jo?o,Cabioc'h, Thierry,Clacens, Jean-Marc,Richard, Frédéric
, p. 135 - 144 (2021/01/04)
Three bimetallic Ni-Co (Ni:Co ratio 1:3, 1:1 and 3:1) and two monometallic (Ni and Co) nanoparticles supported on Al2O3 were synthesized by incipient wet impregnation and characterized by various technics (N2-physisorption, XRD, H2-TPR, CO-chemisorption and elemental analysis). It was demonstrated by XRD that NiCo alloys nanoparticles were present on bimetallic solids. The catalytic properties of all catalysts were determined for the hydrodeoxygenation of m-cresol at 340 °C under 4 MPa of total pressure. It was demonstrated that NiCo alloy developed better deoxygenation catalytic properties than pure Ni metallic phase, these properties being evaluated both by the total reaction rate (kTOT) and the selectivity into deoxygenation products. Indeed, bimetallic NiCo(3:1)/Al2O3 was 1.2 times more active than Ni/Al2O3 and 8.8 times than Co/Al2O3, deoxygenated products being favored on bimetallic catalysts compared to Ni one. In addition, the kTOT values seems to be related to the amount of CO uptakes, indicating that active sites in HDO were of similar nature than those allowing the adsorption of CO, and could be oxygen vacancies which were promoted in bimetallic Ni-Co particles.
Influence of Intracrystalline Ionic Strength in MFI Zeolites on Aqueous Phase Dehydration of Methylcyclohexanols
Milakovi?, Lara,Hintermeier, Peter H.,Liu, Yue,Baráth, Eszter,Lercher, Johannes A.
supporting information, p. 24806 - 24810 (2021/09/08)
The impact of the concentration of hydrated hydronium ions and in turn of the local ionic strength in MFI zeolites has been investigated for the aqueous phase dehydration of 4-methylcyclohexanol (E1 mechanism) and cis-2-methylcyclohexanol (E2 mechanism). The E2 pathway with the latter alcohol led to a 2.5-fold higher activity. The catalytic activity normalized to the hydronium ions (turnover frequency, TOF) passed through a pronounced maximum, which is attributed to the increasing excess chemical potential of the alcohols in the pores, increasing in parallel with the ionic strength and the additional work caused by repulsive interactions and charge separation induced by the bulky alcohols. While the maximum in rate observed is invariant with the mechanism or substitution, the reaction pathway is influencing the activation parameters differently.