A highly efficient oxidation of cyclohexane over Au/ZSM-5 molecular sieve catalyst with oxygen as oxidant

Abstract

A highly efficient oxidation of cyclohexane to cyclohexanol and cyclohexanone is accomplished over calcined Au/ZSM-5 molecular sieve catalyst with oxygen as oxidant.

An Attempt to Selectively Oxidize Methane over Supported Gold Catalysts

“…At higher loadings the selectivity towards the formation of CO and CO 2 increased [50]. In the liquid phase selective oxidation of cyclohexane, gold catalysts have been reported to maintain high selectivities even at conversion \10% [47,49]. However, by a thorough investigation of the reaction mechanism, we delivered proof for the occurrence of a radical-chain autoxidation mechanism.…”

“…A wide variety of supported gold catalysts have been reported to exhibit great performance in selective liquid phase cyclohexane oxidation [47][48][49]. Inspired by the promising results reported on selective oxidation of cyclohexane over gold-based catalyst materials [49], in this publication we have investigated the potential application of supported gold catalysts for the selective oxidation of methane into methanol. Unfortunately, no indication of selective C-H bond activation was observed.…”

Selective liquid phase oxidation of cyclohexane over Pt/CeO2-ZrO2-SnO2/SiO2 catalysts with molecular oxygen

“…Even without the use of radical initiators and free-radical scavengers, the results for both conversion and selectivity are excellent. In particular, the reaction pressure (0.5 MPa or 4.9 atm) employed in the catalytic system is significantly lower than that used with conventional methods (1-1.5 MPa or 9.9-14.8 atm) [4][5][6][7][8][9]. The highest activity is obtained for Pt(5)/CZS/SiO 2 , for which a conversion ratio of 24.1% and a selectivity of 83.4% for KA-oil are achieved.…”

“…5) [2] and MCM-41 (Mobil Composition of Matter No. 41) [3] can convert CyH to KA-oil at 150 ℃ in 1 MPa (9.9 atm) O 2 atmosphere for 2-6 h with a 6%-19% conversion ratio and 92%-100% selectivity, even in the absence of free-radical  scavengers [4,5]. An Au/SiO 2 catalyst, in which gold nanoparticles were embedded in amorphous silica, also exhibited a high catalytic activity of 22.7% for CyH conversion and 80.6% selectivity for KA-oil at 150 ℃ and 1.5 MPa (14.8 atm) O 2 for 3 h, although toxic and explosive tert-butyl hydroperoxide (TBHP) was used as a radical initiator [6].…”

Halloysite Nanotubes Supported Gold Catalyst for Cyclohexene Oxidation with Molecular Oxygen

“…Supported gold catalysts have been extensively studied for a wide range of oxidation reactions including CO oxidation [13], propylene epoxidation [14], the direct synthesis of hydrogen peroxide from oxygen and hydrogen [15,16], oxidation of cyclohexane to KA oil [17][18][19], etc.. Particularly, the partial liquid-phase cyclohexene oxidation using gold catalysts including Au/C and Au/CNTs makes gold even more attractive [20,21].…”