Aerobic one-step oxidation of benzene to phenol on copper exchanged HZSM5 zeolites: A mechanistic study

作者：Tabler Andreas; Haeusser Anette; Roduner Emil^*

来源：Journal of Molecular Catalysis A: Chemical , 2013, 379: 139-145.

DOI：10.1016/j.molcata.2013.08.012

• Benzene oxidation
• Copper zeolite
• Bifunctional catalyst
• Oxygen activation

Various Cu/HZSM5-zeolites were prepared and their catalytic properties were investigated by product analysis via GC/MS chromatography in order to trace down the mechanism of the gas phase one-step oxidation of benzene to phenol with molecular oxygen. Comparison of Cu free and Cu containing zeolites showed that the activation of O-2 takes place at copper centers of the zeolite and high copper loadings lead to high yields of deep oxidation products (CO, CO2). No phenol was formed in the absence of Bronsted acid sites, i.e. on Cu/KZSM5, revealing the bifunctionality of the Cu/HZSM5 zeolite. The yields of the various oxidation products and thus the selectivity toward phenol can be influenced by variation of the relative O-2 concentration in the reaction mixture, indicating the possibility of a stoichiometric use of O-2. The role of the superoxide radical ion O-2 as a reactive intermediate is discussed and a radical ionic reaction mechanism is suggested.

• 出版日期2013-11-15