Low-temperature activation of methane over rare earth metals promoted Zn/HZSM-5 zeolite catalysts in the presence of ethylene

Progress in Nonoxidative Dehydroaromatization of Methane in the Last 6 Years

“…Shan et al applied a series of rare earth metal species (0.1 wt % Eu, Dy, La, Pr, Ce, Gd, Nd, Tb, Sm, and Ho) to modify Zn-based HZSM-5 zeolites (1.35 wt % Zn, Si/Al = 32) by conventional incipient wetness impregnation method. A mixture of methane and ethylene was used as a reactant gas to produce aromatics.…”

Further Steps of Zeolites Toward Industrial Applications

“…Zn/HZSM-5 catalysts known as efficient systems for ethane and propane aromatization (the UOP Cyclar Process) also showed some activity in methane aromatization [69]. At 723 K, methane can easily be activated in the presence of ethylene in the feed and converted to higher hydrocarbons (C 2 C 4 ) and aromatics (C 6 C 10 ), through its reaction over rare metals modified Zn/HZSM-5 zeolite catalysts.…”

Origin of the Ability of α‐Fe2O3 Mesopores to Activate C−H Bonds in Methane

“…The gas flows were regulated by mass flow controllers. The catalyst was pretreated in an O 2 gas flow at 130 8Cf or 2hwith af low rate of 20 mL min À1 and then the reactant mixture of CH 4 and O 2 was switched to the reactor.T he flow rates of CH 4 and O 2 were 30 mL min À1 and 10 mL min À1 ,r espectively.T he composition of the gas exiting the reactor was monitored by an online gas chromatograph equipped with ac arbon molecular sieve (5 ) column and aGDX-502 column in parallel conjunction and athermal conductivity detector and as eparate gas chromatography-mass spectrometer (GC-MS, Finnigan voyager,U SA). The product peaks were determined by calibration with pure reagent in the chromatograms.…”

“…Methane (a main constituent of natural gas, coal-bed gas, biogas, and methane hydrate) is considered as the mosta bundant and least expensive hydrocarbon feed stock available for the production of chemicals. [1][2][3][4][5][6][7] However,t he CÀHb onds in methane,w hicha re the most stable CÀHb onds of all hydrocarbons[ D CÀH = 435 kJ mol À1 ], make it very inert and extremely difficult for directc onversion to higher hydrocarbons or other chemicals. Therefore, high reaction temperature, high pressure, or other harsh conditions are required to activate CÀHb onds of methane in order to react with other reagents or itself.…”

“…Methane (a main constituent of natural gas, coal‐bed gas, biogas, and methane hydrate) is considered as the most abundant and least expensive hydrocarbon feed stock available for the production of chemicals . However, the C−H bonds in methane, which are the most stable C−H bonds of all hydrocarbons [ D C−H =435 kJ mol −1 ], make it very inert and extremely difficult for direct conversion to higher hydrocarbons or other chemicals.…”