负载型Pt-Fe/SiO_2催化剂催化环己烷一步氧化制己二酸

己二酸是合成尼龙-66和尼龙-46纤维的重要原料,并进一步用于生产许多重要的化工产品。工业上的己二酸多采用以硝酸为氧化剂的两步法合成,该工艺不仅工艺复杂,而且对设备有腐蚀作用,还会释放大量的温室气体N_2O。本文以负载型Pt/SiO_2、Fe/SiO_2和Pt-Fe/SiO_2为催化剂,采用过氧化氢和氧气为氧源,研究了环己烷一步氧化制己二酸的绿色合成路线。对催化剂进行ICP、BET比表面积、XRD、TEM等表征,结果表明,Pt-Fe/SiO_2催化剂中不存在与Pt或Fe对应的衍射峰。在最佳反应条件下,用高压釜进行了催化剂性能评价,结果表明,Pt-Fe/SiO_2催化活性略优于Pt/SiO_2和Fe/SiO_2。在环己烷转化率为28%的情况下,己二酸选择性达到33%。

One step oxidation of cyclohexane to adipic acid on supported Pt-Fe/SiO2 catalysts

Adipic acid (AA) is an important raw material for synthesis of nylon-66 and nylon-46 fiber,which are further used to produce many important chemicals.The majority of adipic acid in industry is synthesized via a two-step process using nitric acid as oxidant.The process is not only complex,but also has the problem of equipment corrosion.More importantly,it releases a lot of the greenhouse gas nitrous oxide.Herein,a green synthetic route for one-step oxidation of cyclohexane (CH) to AA was investigated using supported Pt/SiO₂,Fe/SiO₂ and Pt-Fe/SiO₂ catalysts.Hydrogen peroxide (H₂O₂) and oxygen (O₂) were used as oxygen sources.The catalysts were characterized by ICP,BET,XRD,TEM,and so on.Performance tests were carried out using autoclave under the optimum conditions.XRD patterns revealed that no reflections corresponding to either Pt or Fe were present in Pt-Fe/SiO₂ catalyst.In terms of catalytic activity,Pt-Fe/SiO₂ exhibited slightly better compared to Pt/SiO₂ and Fe/SiO₂.The selectivity of AA (S_AA) reached 33% with the conversion of cyclohexane (C_CH) of 28%.