The Conversion of Methanol into Higher Hydrocarbons Catalyzed by Gold

Abstract

Gold/zinc oxide catalysts prepared by coprecipitation and containing gold particles of approximately 6 nm in diameter are active in the conversion of methanol to higher hydrocarbons under mild conditions. Conversions exceed 97 % under the selected experimental conditions at reaction temperatures of 350 °C, with a turnover number of 0.02 s−1. Both alkanes and alkenes up to C6 are formed, with a selectivity of approximately 44 %C hydrocarbons and 56 %C dimethyl ether. The addition of zeolite‐Y in composite catalysts modifies the product spectrum slightly. Ethene and propene dominate the alkenes formed above 450 °C if a 1:1 HY:Au/ZnO composite is used; the dominant alkane under these conditions is methane. At 475 °C only three hydrocarbons are present with selectivities of 13 (methane), 39 (ethene), and 48 % (propene). The carbon−carbon bond formation was not seen in earlier work when syngas (CO plus H2) was converted with the same Au/ZnO catalyst at high pressure to form mixtures of alcohols and hydrocarbons. This suggests that the formation of higher hydrocarbons from methanol is inhibited in the presence of CO and/or H2, probably due to competitive CO adsorption on the gold surface.

Hydrotreatment of Kraft Lignin to Alkylphenolics and Aromatics Using Ni, Mo, and W Phosphides Supported on Activated Carbon

“…The latter is likely not inert under the prevailing reaction conditions and may be converted to gas-phase components. 60,61…”

“…In addition, methoxy removal by hydrogenolysis reactions may also occur, as shown by model component studies, , leading to the formation of methanol. The latter is likely not inert under the prevailing reaction conditions and may be converted to gas-phase components. , …”

“…The latter is likely not inert under the prevailing reaction conditions and may be converted to gas-phase components. 60,61 When using the metal phosphide catalysts and particularly 20NiMoP/AC at optimized conditions, high yields of alkylphenolics are obtained, with smaller amounts of aromatics, low amounts of overhydrogenated alkanes, and essentially no char. This means that the catalysts are very reactive at reported optimized conditions and promote hydrocracking reactions as well as methoxy removal reactions while being less reactive for hydrodeoxygention of alkylphenolics, leading to aromatics and hydrogenation reactions of the C−C bonds in the aromatic rings to give alkanes.…”