Fe(H)-5A分子筛催化剂在甲醛低温催化氧化反应中的催化性能

Performance of Fe(H)-5A Molecular Sieve Catalyst in Low Temperature Oxidation of Formaldehyde

以5A分子筛为前体,使用离子交换法制备了Fe(H)-5A分子筛系列催化剂,该系列催化剂对低浓度甲醛的低温催化氧化反应有显著的催化效果.甲醛初始转化温度为70～100℃,100%转化温度为160～190℃.考察了制备条件对催化剂的催化性能的影响.实验结果表明,酸处理可以促进催化反应过程中部分氧化产物甲酸的产生;而提高煅烧温度可以减少甲酸的生成,使甲醛完全氧化为CO2和水.同时,对部分试样进行了x射线衍射表征,发现制备过程对分子筛的晶格结构会造成一定程度的破坏.

A series of Fe(H)-5A molecular sieve catalysts were prepared by ion-exchanging and using 5A molecular sieves as precursors. The catalyst was obviously active to oxidation of very low concentration formaldehyde at low temperature. The initial temperature of formaldehyde conversion was 70-100° and the temperature of its completion was 160-190°C. Effects of preparation conditions on catalyst performance were investigated. Acid treatment would promote production of formic acid. Raising calcination temperature of catalyst could effectively decrease production of formic acid and completely oxidize formaldehyde to carbon dioxide and water. Some samples were examined by means of XRD that structure of catalyst was somewhat damaged during preparation.