Methylation of naphthalene by methane-carbon-13 over copper-exchanged silicoaluminophosphate

Further evidence for the oxidative methylation of benzene with methane over zeolite catalysts

“…As mentioned earlier in the introduction section, previous studies by Long et al [2,13] have demonstrated using 13 C labelled methane that the source of methyl groups in the methylated aromatic products of the reaction of methane with naphthalene, toluene and phenol in a high pressure batch reactor over substituted aluminophosphate molecular sieves was predominantly the methane reactant. This then implied actual activation of the methane molecule.…”

“…These substrates would be those that have previously been reported to undergo direct methylation with methane over aluminophosphate catalysts such as naphthalene, toluene and phenol [2,13]. Other substrates that model petroleum, coal and liquefaction residue structures (eg benzene, diphenylmethane, biphenyl, diphenyl sulfide, diphenyl ether and dinaphthol) [3] that have also been demonstrated to have methane incorporated into them over Cu-beta, H-beta and CuZSM-5 should also be investigated.…”

“…The methylation of benzene with methane over zeolite catalysts in both high pressure flow reactor [5] and batch reactor [4] has also been reported. However, the high pressure flow reactor study [5] demonstrated, through the use of 13 C labelled methane, that the methyl groups in the methylated aromatic products did not originate from the methane reactant.…”

Green chemistry perspectives of methane conversion via oxidative methylation of aromatics over zeolite catalysts

“…These workers then subsequently confirmed using a 13 CH 4 isotropic tracer experiment that the methyl groups in the substituted naphthalene products were derived mainly from methane, thereby indicating direct methylation of naphthalene. 23 Thus, for example, the GC-mass spectrometric analysis of the products of the reaction using 13 CH 4 showed that the methylnaphthalene formed from naphthalene contained principally one 13 C atom and the dimethylnaphthalene contained two 13 C atoms per molecule. A further confirmation was also obtained from 1 H NMR spectra of the products, which indicated an estimate of 73% 13 C in the methyl groups of the products of the 13 CH 4 experiment.…”

“…This route has been the subject of some recent investigations. [21][22][23][24][25][26][27][28][29][30][31][32] For example, the direct methylation of naphthalene, toluene and phenol with methane over aluminophosphate molecular sieves in a high pressure batch reactor has been demonstrated. 21,22 More recent batch reaction investigations 25,26 have also revealed the incorporation of methane in the presence of Cu-beta, H-beta and CuZSM-5 into a variety of organic substrates (eg.…”