铁改性石墨相氮化碳催化苯酚羟基化反应合成二酚

石墨相氮化碳(g-C3N4)以其独特的电子结构和化学特性引起了广泛关注。以双氰胺和硝酸铁为原料，制备了Fe改性的石墨相氮化碳(Fe/ g-C3N4)，采用红外光谱、XRD和N2吸附-脱附等分析手段对g-C3N4和 Fe/g-C3N4 进行了表征，并用以催化苯酚羟基化反应合成二酚，研究了Fe/ g-C3N4催化性能的影响因素。结果表明，Fe/ g-C3N4材料具有良好的介孔结构，Fe的引入改变了g-C3N4层状结构的层间距。当苯酚/H2O2摩尔比为2/1、铁负载量为0.7%(质量分数)、反应温度为50 ℃、反应时间为6 h时，苯酚的转化率达到39.7%，邻苯二酚和对苯二酚的总选择性为85.8%。重复实验结果证实该催化剂可以重复使用。

Hydroxylation of Phenol to Produce Dihydroxybenzene Catalyzed by Iron Modified Graphitic Carbon Nitride

Graphitic carbon nitride (g-C3N4), possessing unique electronic and chemical properties, has attracted extensive attention from researchers. By using ferric nitrate and dicyandiamide as precursors, a series of Fe modified graphitic carbon nitride (Fe/ g-C3N4) were prepared and used for catalyzing the hydroxylation of phenol to dihydroxybenzene. Fe/ g-C3N4 and g-C3N4 were characterized by FT-IR spectra, XRD and N2 absorption-desorption isotherms. Effects of reaction conditions on the catalytic performance of Fe/ g-C3N4were studied. Results show that Fe/ g-C3N4 has uniform mesoporous structure and the layer spacing of g-C3N4 is changed after the introduction of Fe. Under optimized conditions, 39.7% phenol conversion and 85.8% catechol and hydroquinone selectivity are obtained, with Fe mass fraction of 0.7%, molar ratio of phenol to H2O2 of 2/1, reaction temperature of 50 ℃, and reaction time of 6 h. The reusability of the Fe/ g-C3N4 catalyst is very good by the recycling test.