摘要
采用共沉淀法与柠檬酸法合成了铁酸镁 ,并用X射线衍射和红外光谱等对不同样品进行了表征 .以三甲基苯酚为原料 ,以铁酸镁为催化剂 ,以双氧水为氧化剂 ,实现了一步羟化为三甲基对苯二酚 (维生素E重要中间体 )的目的 .详细考察了催化剂、温度、溶剂和双氧水等因素对该反应体系的影响 .结果表明 ,铁酸镁对该反应体系具有很好的催化效果 ,较常用的羟化催化剂TS 1分子筛等的催化性能好得多 .该过程可以进一步研究发展成为一个环境友好催化过程 .
A new method for synthesis of trimethylhydroquinone (TMHQ) which is one of main compounds for synthesis of vitamin E is reported. All commercial processes for synthesis of TMHQ are via 2,3,6-trimethylphenol (TMP) and have disadvantages in their multi-steps and production of pollutants. In order to decrease the pollution and synthesis steps, it is desirable to develop a single-step process for synthesis of TMHQ, i.e. direct hydroxylation of TMP to TMHQ. In this paper, the catalyst MgFe 2O 4, for hydroxylation of TMP with H 2O 2 as an oxidant, was synthesized via coprecipitation method from an aqueous solution containing Fe(NO 3) 3·9H 2O, Mg(NO 3) 2·6H 2O and NaOH. The XRD peaks of the catalyst showed that the as-prepared sample has the crystal phase with spinel structure, confirmed also by its IR spectrum. The hydroxylation of TMP with H 2O 2 over the catalyst and some factors affecting on the reaction, such as catalyst samples, reaction temperature, solvents, and H 2O 2 concentration and addition modes, were studied. The results showed that the catalyst MgFe 2O 4 is of high activity for TMP hydroxylation and high selectivity for TMHQ formation. Under the same reaction conditions, the TMHQ selectivity over MgFe 2O 4 is higher than that over TS-1 and Ti-MCM-41, furthermore, the reaction time is shortened greatly.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第8期635-638,共4页
关键词
铁酸镁
三甲基苯酚
羟基化
过氧化氢
三甲基对苯二酚
magnesium ferrite, trimethylphenol, hydroxylation, hydrogen peroxide, trimethylhydroquinone
