醛酮树脂基非金属催化剂催化氧气氧化苯制备苯酚

Oxidation of benzene to phenol over aldehyde-ketone resin based metal-free catalyst

苯酚是一种具有广泛应用价值的化工原料,氧气直接氧化苯制备苯酚是一条绿色的路径。本文设计并制备了一种新型醛酮树脂基非金属催化剂用于氧气直接氧化苯制备苯酚。通过X射线衍射仪、傅里叶变换红外光谱仪、扫描电镜、X射线光电子能谱和N_(2)吸附-脱附等技术对催化剂的形貌、结构进行了表征。结果表明,制备的催化剂是具有大量羟基和羰基官能团的无定形碳材料,不同的酮对催化剂官能团的含量有影响。考察了所制备的催化剂催化氧气直接氧化苯制备苯酚反应的性能,优化了反应条件。在最佳反应条件下,苯酚的产率达到16.3%,其催化性能可与金属催化剂相媲美。此外,通过动力学研究表明该反应为一级反应并计算了各步骤的反应速率常数。结合表征、动力学实验和对照实验得出催化剂表面丰富的酮羰基是反应的活性位点,并据此提出了反应机理。

Phenol is an industrial chemical with a wide range of applications.Direct oxidation of benzene with molecular oxygen is a green route to synthesize phenol.A novel aldehyde-ketone resin-based nonmetallic catalyst was designed and prepared for direct oxygen oxidation of benzene to phenol.The morphology and structure of the catalysts were characterized by XRD,FTIR,SEM,XPS and N_(2)adsorption-desorption.The results showed that the prepared nonmetallic catalysts were amorphous carbon materials with abundant functional hydroxyl and carbonyl groups which were affected by the ketone sources.In addition,the reaction conditions were optimized and a yield of phenol of 16.3%was achieved.The performance of the papered catalyst was comparable to that of metal catalysts.Besides,kinetic studies showed that the reaction was a first-order reaction and the rate constants for each reaction step were calculated.Combining characterization,kinetic experiments,and controlled experiments,we found that the abundant ketone groups on the catalyst surface were the active sites.Based on this,the reaction mechanism was proposed.