Partial Oxidation of Methane Over Co-ZSM-5: Tuning the Oxygenate Selectivity by Altering the Preparation Route

Abstract

For the first time the possibility to partially oxidize methane to methanol and formaldehyde at low temperature over Co-ZSM-5 using air is shown. The influence of the preparation method on the nature of the cobalt species is investigated. In addition, the catalytic activity and selectivity for methane oxidation as a function of the cobalt speciation is discussed. Based on UV-vis-NIR and FT-IR spectroscopy, H 2 -TPR, TEM and kinetic measurements it is concluded that cobalt in ion-exchange positions results mainly in the formation of formaldehyde, while larger Co-oxide particles prepared by impregnation result in the formation of methanol.

Synthesis of ZSM-5 zeolite from coal fly ash and rice husk: characterization and application for partial oxidation of methane to methanol

“…Furthermore, flushing was carried out using nitrogen gas to remove organic impurities, water vapour and excess oxygen in the reactor. The condition of the reaction was adapted from the work reported by Krisnandi et al [9] and Bezniz et al [11]. The first set of experiments was carried out at 150 o C with reaction time of 30 min and 60 min, and CH4 pressure (Pmethane) of 0.75 Bar in 200 cm 3 stainless steel vessel.…”

Partial oxidation of methane to methanol over catalyst ZSM-5 from coal fly ash and rice husk ash

“…The condition of the reaction was adapted from the work reported by Krisnandi et al. [1] and Bezniz et.al [7]. The first set of experiments was carried out at 150 o C with reaction time of 30 minutes and 60 minutes, and CH 4 pressure (Pmethane) of 0.75 Bar in 200 cm 3 stainless steel vessel.…”

“…The activity of ZSM-5 and Co/ZSM-5 from fly ash and rice husk ash inferior compared to the pro-analysis materials because ZSM-5 from fly ash and rice husk has lower surface area than ZSM-5 pro-analysis materials. The cobalt-loaded ZSM-5 catalysts gave higher conversion than the ZSM-5 without cobalt-loaded because impregnated Co/ZSM-5, mainly containing cobalt oxide species at the zeolite outer surface, were more selective towards methanol [7] The mechanisms (modified from [13]) that occurred during the partial oxidation of methane to methanol are as follows:…”

“…Beznis et al.. [7] has been investigated the oxidation of methane to methanol and formaldehyde over Co-ZSM-5 molecular sieves. Eugeny et al [8] also has been investigated about oxidation methane to methanol on the surface of FeZSM-5 zeolite.…”

An Attempt to Selectively Oxidize Methane over Supported Gold Catalysts

“…Direct methane valorisation, surpassing the costly syngas production, still attracts major attention in both academia and industry [8][9][10][11][12][13][14][15][16][17][18][19]. Although proof-of-principle studies have been successful, it has not led to any commercial application yet, mainly due to the low yields and high costs.…”