新型催化剂V2O5/ZSM-5用于液体石蜡催化氧化合成脂肪酸

摘要

以偏钒酸铵为主要原料,ZMS-5型分子筛为载体,采用共沉淀法制备了V2O5/ZSM-5催化剂,将其用于液体石蜡催化氧化合成了脂肪酸.利用能量色散X射线荧光光谱仪对所制备的催化剂进行表征,说明V2O5/ZSM-5催化剂制备成功.利用X射线衍射仪、X射线光电子能谱仪对反应前后的催化剂进行表征,说明V2O5/ZSM-5在液体石蜡氧化过程中只起催化效果.利用傅里叶变换红外光谱仪对所制备的氧化产物进行表征,证明了氧化产物中确有脂肪酸的存在.同时考察了在合成脂肪酸的过程中反应温度、反应时间、催化剂用量、反应气氛等工艺条件对液体石蜡催化氧化合成了脂肪酸效果的影响.实验结果表明:反应温度为150℃、反应时间为8h、催化剂用量为0.1g时,在纯氧气氛下可以合成性能最优的脂肪酸,其酸值为17.33mg(KOH)/g、皂化值为33.52mg(KOH)/g.%Using ammonium metavanadate as main raw material and Zeolite Socony Mobil-5(ZSM-5) as the carrier,the V2O5/ZSM-5 catalyst was prepared by coprecipitation and it was applied to the catalytic oxidation of liquid paraffin for the synthesis of fatty acid. The catalyst was characterized by Energy Dispersive X-Ray Fluoresence Spectrometer(EDX). EDX analysis indicated that the V2O5/ZSM-5 catalyst was prepared successfully. The catalysts before and after reaction were analyzed by X Ray Diffraction(XRD)and X ray Photoelectron Spectroscopy(XPS),which suggested that V2O5/ZSM-5 only play the catalytic role in the oxidation process of liquid paraffin. The prepared oxidation product was characterized by Fourier Transform Infrared Spectrometer(FTIR),and it was found that the fatty acid existed in the oxidation product. Meanwhile,the effect of reaction temperature,reaction time,dosage of catalyst and gas atmosphere on the performance of fatty acid was investigated. The experimental results showed that the optimal conditions for preparing fatty acid are as follows:temperature 150℃,reactionTime 8h,dose of catalyst 0.1g,and with pure oxygen. The acid value and the saponification of the product were 17.33mg(KOH)/g and 33.52mg(KOH)/g,respectively.