Hydrocarbon formation from methane by a low-temperature two-step reaction sequence

Direct conversion of methane under nonoxidative conditions

“…C-C bonds were supposed to be created during the hydrogenation step. Since the reactivity of the CH x surface intermediates formed from CO and CH 4 was quite similar, the authors suggested that the chain-growth probability would depend on the metal-carbon bond strength and that the mechanism of C-C bond formation in the twostep route should be related to that occurring in the FisherTropsch reaction [13,14]. Van Santen and co-workers also demonstrated that the homologation of olefins (C 2 H 4 , C 3 H 6 , C 2 H 2 , etc.)…”

“…Generally, three forms of carbon, referred to as C α , C β , and C γ , are formed in the first step, which were distinguishable by the temperature at which they react with H 2 [13]. The maximum yield of C 2+ products on a Ru/SiO 2 catalyst was reported to be in coincidence with a maximum surface coverage by C β [20].…”

“…Furthermore, the authors claimed that the addition of CO and CO 2 to the CH 4 feed (less than 3%) led to a remarkable increase in the stability of the catalyst. By using a 13 CO and CH 4 mixture as the feed to conduct the reaction, the authors suggested that CO dissociated on the Mo sites to form the active carbon species CH x . The dissociated oxygen species [O] from CO might react with the surface inert carbon species to regenerate CO, resulting in the suppression of coke formation on the catalyst.…”

Novi petrokemijski procesi na temelju izravne pretvorbe metana

“…NOCM je proces koji se sastoji od dvaju stupnjeva. 15,16 Santen i sur. 15 su iz metana proizveli alkane C 2 -C 6 pri atmosferskim tlaku preko mehanizma prikazanog na slici 5.…”

Thermocatalytic CO2-Free Production of Hydrogen from Hydrocarbon Fuels

“…It should be noted, however, that there is no universal agreement among different groups of researchers regarding the choice of the most efficient metal catalyst for methane decomposition. For example, it was demonstrated [12] that the rate of methane activation in the presence of transition metals followed the order: Co, Ru, Ni, Rh > Pt, Re, Ir > Pd, Cu, W, Fe, Mo. The authors [10,13] have found Pd to be the most active catalyst for methane decomposition, whereas, Ni was the catalyst of choice in the publication [14], and Fe and Ni in publications [15,16].…”