A simple and efficient zeolite catalyst for toluene oxidation in aqueous media

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• 作者：Bin Du ; Song-Il Kim ; Lan-Lan Lou ; Aizhong Jia ; Gaixia Liu ; Ben Qi ; Shuangxi Liu ; ^{sxliu@nankai.edu.cn}
• 关键词：Aqueous media ; Toluene oxidation ; Heterogeneous catalysis ; Alkali-treatment
• 刊名：Applied Catalysis A: General
• 出版年：2012
• 出版时间：28 May, 2012
• 年：2012
• 卷：425-426
• 期：Complete
• 页码：191-198
• 全文大小：790 K

文摘

In this work, it was found that alkali-treated zeolites could efficiently catalyze oxidation of toluene with H₂O₂ in aqueous media. No heavy metals or their oxides were employed in the synthesis of catalyst and no additives were used in this catalytic system. Through optimizing the experimental conditions, alkali-treated HZSM-5 exhibited good catalytic activity for toluene oxidation in only 5 h at a low temperature (below 100 ¡ãC): 32.0 % conversion of toluene with selective formation of 25.0 % benzaldehyde, 20.8 % benzyl alcohol and 27.5 % benzoic acid. Moreover, the results of reusability studies indicated that alkali-treated HZSM-5 was a durable and green catalyst for toluene oxidation in aqueous media. The changes in acidities and textural features of the zeolites induced by alkali-treatment were characterized by ammonia temperature programmed desorption (NH₃-TPD) and X-ray powder diffraction (XRD), respectively. The results indicated the reactivity for toluene oxidation could be related to the amount of species Al and AlOH in this system. A probable redox mechanism for toluene oxidation catalyzed by alkali-treated zeolites in aqueous media was proposed in this work.