The Catalytic Study On The Oxidation Of Cyclohexanone Intoε-caprolactone And The Conversion Of Ch₃Br Into P-xylene Or Light Olefins

ε-Caprolactone is used for the synthesis of polycaprolactone which is well known in the field of biochemistry, coating and electronics. It has been growing attention that carbon materials were used as metal-free catalysts. We found that carbon materials showed excellent activity and selectivity in the Baeyer-Villiger (B-V) oxidation of cyclohexanone using dioxygen (O2) as oxidant and benzaldehyde as sacrificial agent. Among them graphite was found to be the most suitable for the formation of lactones from cyclic ketones, the cyclohexanone conversion and s-caprolactone yield is up to99.6%and99.0%, respectively, at55℃for3h. By combination of characterization results (BET, SEM, Raman, XPS), it is deduced that the catalytic activity has no relationship with the carbonyl number on the surface of catalysts. The carbon materials with lower ID/IG ratio show higher catalytic performance. The use of the metal-free catalysts enables a green process for the production of lactones from ketones under mild reaction conditions.With the shortage of petroleum resources, the utilization of natural gas has attracted much attention. A new process for preparation of para-xy\ene (p-xylene) by the alkylation of benzene with CH3Br is proposed for the first time. The alkylation of benzene with CH^Br is catalyzed by HZSM-5or modified HZSM-5. The benzene conversion and p-xylene selectivity can reach up to43.6%and91.2%, respectively, and the molar ratio of p-xylene in the liquid product is up to28.7%at475℃over P2O5-and ZnO-modified HZSM-5. In addition, by combining the characterization results (XRD, SEM, BET, NH3-TPD), it is deduced that the catalytic activity depends on the appropriate acid both of inner and external surface acid of catalysts, while the para-selectivity depends on the weak external surface acid of catalysts. The rapid deactivation of catalyst is mainly caused by carbon deposition. CHsBr could be prepared by the catalytic bromination of natural gas (methane), and benzene could be prepared from methane dehydroaromatization. It is approved that p-xylene could be synthezied from the natural gas.On this basis, a new process for preparation of light olefin from CH3Br is proposed. Different silicon content and metal oxide modified SAPO-34were investigated in the reaction. It is found that CH^Br conversion increases with the increase of silicon content; the introduction of metal oxides (MgO, MnO2, CO3O4,3, Ni2O3) would decrease the catalytic activity and increase the ethylene selectivity; while the introduction of metal oxides (ZnO, CaO) increases the catalytic activity. In addition, by combination of characterization results (XRD, SEM, BET, NH3-TPD), it is deduced that CH3Br conversion depends on the strong acid on the surface of catalysts, while ethylene selectivity depends on the weak acid on the surface of catalysts.