对甲苯磺酸/活性炭/双氧水体系选择氧化苯乙烯生成苯甲醛(英文)

Oxidation of styrene to benzaldehyde by p-toluenesulfonic acid using hydrogen peroxide in the presence of activated carbon

以双氧水为氧化剂,研究了对甲苯磺酸和活性炭体系选择氧化苯乙烯生成苯甲醛反应性能。考察了反应时间、温度、催化剂用量、苯乙烯和双氧水摩尔比等对苯乙烯选择氧化性能的影响.结果表明,对甲苯磺酸和活性炭的用量和用量比是一个重要因素,但对甲苯磺酸的酸性对氧化反应活性影响不大.对甲苯磺酸和双氧水相互作用,经非自由基过程氧化苯乙烯.通过分解双氧水产生氢氧自由基,活性炭显著提高对甲苯磺酸和双氧水体系氧化苯乙烯活性.在惰性或还原气氛中高温处理活性炭能降低其表面含氧基团数量,增加碱性,有效分解双氧水,产生相对较多的OH自由基.与未处理的活性炭相比,高温处理的活性炭进一步提高了对甲苯磺酸和双氧水体系氧化苯乙烯活性,但降低了苯甲醛选择性.经磺化,在活性炭表面引入的–SO_3H基团比含氧基团(–OH,–COOH)更有效与双氧水作用氧化苯乙烯.

The selective oxidation of styrene to benzaldehyde catalyzed byp-toluenesulfonic acid （p-TsOH） in the presence of activated carbon （AC） was investigated with H2O2 as the oxidant. The reaction pa-rameters of reaction time, temperature, catalyst mass, and styrene/H2O2 molar ratios were evalu-ated. A strong promoting effect of AC on thep-TsOH/H2O2 system was observed. The appropriate ratio and amounts of AC andp-TsOH were an important factor. The acidity ofp-TsOH does not play a significant role.p-TsOH reacted with H2O2 by a non-radical process to oxidize styrene. The func-tion of the AC was to activate H2O2and to help thep-TsOH/H2O2 system in styrene oxidation. The reduction of oxygen containing groups （–OH, –COOH） on AC by a high temperature treatment or introduction of –SO3H groups onto AC affected the styrene conversion. The –SO3H groups were more effective than the oxygen-containing groups on the AC in promoting styrene oxidation.