氨水蒸气处理Fe-ZSM-5分子筛催化N2O氧化苯制苯酚

Direct Oxidation of Benzene to Phenol by N2O over Fe-ZSM-5 Zeolites Obtained via Ammonia-Steaming Treatment

在硅烷偶联剂(3-环氧乙基甲氧基丙基)三甲氧基硅烷(GPTMS)作用下合成了多级孔结构Fe-ZSM-5,采用氨水蒸气对Fe-ZSM-5分子筛进行后处理。利用XRD、SEM、N2吸脱附、UV-vis及NH3-TPD等方法对处理的Fe-ZSM-5进行了表征,并考察了处理后的沸石分子筛催化N2O氧化苯制苯酚的催化性能。结果表明,氨水蒸气相较于水蒸气处理的Fe-ZSM-5分子筛骨架结构和孔结构变化不大,但保留了更多的中强酸酸中心和非骨架活性铁物种,在苯制苯酚反应中表现出更好的催化活性。

Hierarchical Fe-ZSM-5 was synthesized with the aid of 3-glycidoxypropyltrimethoxysilane (GPTMS) and then was modified by the ammonia-steaming post treatment. Various techniques, such as XRD, SEM, N2 adsorption-desorption, UV-vis and NH3-TPD were used to characterize the as-obtained and modified hierarchical Fe-ZSM-5. The direct oxidation of benzene to phenol using N2O as the oxidizing agent was conducted on the ammonia-steaming treated Fe-ZSM-5. The results showed that compared to the steaming treated Fe-ZSM-5 catalysts, ammonia-steaming treated hierarchical Fe-ZSM-5 catalysts preserved more mediate strong acid sites and ex-framework iron active species, thus exhibited a higher catalytic activity in the catalytic oxidation of benzene to phenol with N2O, while the frame structure and pore structure of Fe-ZSM-5 was almost unchange.