以CoMn2O4为催化剂氧化二甲苯的研究

Study on the Oxidation of Xylene with CoMnO as Catalyst

探索催化剂的制备条件,包括搅拌温度、干燥温度、煅烧温度及煅烧时间对二甲苯氧化效果的影响,结果表明煅烧温度对氧化效果的影响最为明显。在其它制备条件(搅拌温度为60℃、干燥温度为60℃和煅烧时间为3 h)不变的前提下,通过改变煅烧温度(温度分别350、450和550℃),比较3种二甲苯氧化难易以及不同煅烧温度下氧化同一构型二甲苯的差异。整体而言,煅烧温度为350℃的催化剂性能最佳。邻、间和对3种二甲苯完全氧化的温度相差约15℃,其中,邻二甲苯最难氧化,完全氧化需260℃,间二甲苯次之,对二甲苯最易氧化。与此同时,利用XRD、XPS、N2吸附-脱附和H2-TPR等表征手段来分析煅烧温度造成3种不同构型二甲苯氧化程度差异性的原因。

In this experiment,the effect of preparation conditions,including stirring temperature,drying temperature,calcination temperature and time on the catalytic performance for xylene oxidation was investigated.The experimental results indicated that calcination temperature was the most significant influencing factor on oxidation.When stirring temperature is 60℃,drying temperature is 60℃and calcination time is 3 h,the effect of the calcination temperature(350℃,450℃,550℃)on the difficulty degree of oxidation of these three xylenes and the difference of xylene oxidation with same configuration were investigated.Overall,catalyst with calcination temperature of 350℃was the best,and the three isomeric xylenes had a complete oxidation difference of about 15℃.Among them,o-xylenes was the most difficult to be oxidized,and the temperature required for complete oxidation was 260℃.m-Xylene was the second difficult to be oxidized,followed by p-xylene.Meanwhile,XRD,XPS,N2 adsorption and desorption,H2-TPR and other characterizations were used to analyze the reason why calcination temperature caused the difference in oxidation degree among the three different configurations of xylene.