Hydrogenolysis Of Phenols Research Articles

Catalytic hydropyrolysis of lignocellulosic biomass to BTX and biofuels over zeolite beta based catalysts

Catalytic hydropyrolysis of eucalyptus leaves was investigated in a batch reactor over four catalysts (H-BEA, Ni/BEA, Ni/Fe-BEA and Fe/BEA). HBEA catalyst exhibited a higher monoaromatic hydrocarbons (MAHs) selectivity compared to non-catalytic pyrolysis. However, the selectivity to polyaromatic hydrocarbons (PAHs) was not significantly reduced by the addition of a protonic zeolite. The highest cycloalkanes selectivity (78.5%) was observed over Ni/BEA, owing to its high concentration of Ni sites as well as acid sites, facilitating the hydrogenation and ring-opening of polyaromatic hydrocarbons together with the hydrodeoxygenation of phenols. In contrast, the Ni/Fe-BEA exhibits the highest selectivity of MAHs, suggesting the Ni-Fe species facilitate the partial hydrogenation of PAHs and hydrogenolysis of phenols but restrict the further hydrogenation of aromatic monomers. Moreover, the reduction of CO to CH4 was restricted over Ni-Fe/BEA compared to Ni/BEA. A high selectivity of phenols and PAHs was detected over Fe/BEA due to the high oxophilicity but low hydrogenation activity of Fe species, hindering the hydrogenation of PAHs and HDO of phenols. The spent Ni/BEA and spent Ni/Fe-BEA catalysts exhibited a higher surface area and pore volume as well as lower mass of deposited carbon compared to spent HBEA and spent Fe/BEA catalysts, suggesting the catalyst deactivation was restricted by hydrogenation metal (Ni, Ni-Fe) and dissociated H species. Besides, high H2 pressure promoted the hydrogenation and ring-opening of polyaromatic hydrocarbons, and high reaction temperature hindered the hydrogenation of MAHs to cycloalkanes. The highest selectivity to MAHs (85.1%) with a 62% selectivity of BTEX was observed over Ni/Fe-BEA catalyst at 400 °C and an initial H2 pressure of 3.0 MPa.

Hydrodeoxygenation of Anisole over Silica-Supported Ni2P, MoP, and NiMoP Catalysts

Ni2P/SiO2, MoP/SiO2, and NiMoP/SiO2 with different Ni/Mo molar ratios were prepared by temperature-programmed reduction (TPR). Their structural properties were characterized by N2 sorption, X-ray diffraction (XRD), CO chemisorption, X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed desorption (H2-TPD), and NH3 temperature-programmed desorption (NH3-TPD). Their performances for the hydrodeoxygenation (HDO) of anisole were tested in a fixed-bed reactor. It was found that there were mainly three reactions that occurred during the HDO, i.e., the demethylation of anisole, the hydrogenolysis of phenol, and the hydrogenation of benzene. The HDO activities decreased in the sequence of Ni2P/SiO2 > NiMoP/SiO2 > MoP/SiO2. The NiMoP/SiO2 catalysts with larger Ni/Mo ratios had higher activities. In the phosphides, the Niδ+ and Moδ+ sites bearing small positive charges acted not only as Lewis acid sites for the demethylation but also as metal sites for the hydrogenolysis and hydrogenation. The Niδ+ site...

Promotion of coal liquefaction by iodomethane. 2. Reaction of coal model compounds with iodomethane at coal liquefaction temperatures

The reactions of iodomethane with a number of simple organic substances representative of structural groups in coal have been studied in an attempt to explain the success of iodomethane in promoting coal liquefaction. Iodomethane promotes dehydrogenation of hydroaromatic rings under nitrogen, hydrogenation of aromatic rings, hydrogenolysis of phenols and phenol ethers, and the conversion of pyridine heterocycles to naphthalene and its derivatives under hydrogen. In the presence of molecular hydrogen, hydrogen iodide is as affective as iodomethane. This suggests that iodine is the important reactive moiety and probably functions in hydrogenation and hydrogenolysis by catalyzing the formation of hydrogen radicals from hydrogen gas

Platinum-catalysed hydrogenolysis of phenol to benzene

Benzene is obtained during reduction of phenol by hydrogen in the presence of platinum black under mild conditions.

Electrolytic hydrogenation and hydrogenolysis of phenols at platinum black electrodes

Electrochemical reduction of phenols at platinum black electrodes in ethanolic hydrochloric acid, at atmospheric pressure and room temperature, forms aromatic and aliphatic hydrocarbons as well as ketones and alcohols. The products resemble those from non-electrochemical hydrogenation.

Selectivity of Group VIII Metals for the Catalytic Hydrogenation and Hydrogenolysis of Phenol

The hydrogenation of phenol has been investigated over group VIII metals by a gas chromatographic pulse technique. Major products were found to be cyclohexanone and cyclohexanol, but benzene, cyclohexane and other hydrocarbons were also formed. The relative amount of cyclohexanol over cyclohexanone formed during the hydrogenation varied by a factor of about 100 depending on both catalyst and reaction temperature. This result was interpreted in terms of the relative catalytic activity of metals for the consecutive reaction : [chemical formula] The initial product due to the breaking of the carbon-oxygen bond was benzene rather than cyclohexane even when cyclohexanol or cyclohexanone was injected in the presence of hydrogen. This unusual result was briefly discussed.

Catalytic transfer hydrogenolysis of phenols and aromatic amines

Catalytic transfer hydrogenolysis of phenols and aromatic amines

Hydrogenolysis of phenols in middle oils from coal hydro‐genation

AbstractWhen the middle oils obtained from the hydrogenation of coal were hydrogenated at 450° and 475° c. in a stainless‐steel autoclave in the absence of any added catalyst, very little of the phenolic material was convened to neutral products. Whereas the original material contained only 2·9%, phenols boiling below 230° c., the hydrogenated product (at 475° c.) contained 9·1% (based on the charge) phenols boiling below this temperature. When the phenolic fraction of the middle oil was isolated before hydrogenolysis and then treated, more conversion of high‐boiling to low‐boiling phenols occurred, but this was accompanied by elimination of oxygen and the production of about 20% neutral material.