MnO_x/TiO_2-Al_2O_3催化剂在超临界水氧化中的应用

以TiO2-Al2O3为载体、MnOx为活性组分制备了MnOx/TiO2-Al2O3催化剂,通过差热-质谱、X射线衍射、程序升温还原、BET测定比表面积等方法对MnOx/TiO2-Al2O3催化剂进行了表征;考察了MnOx/TiO2-Al2O3催化剂前体的分解过程及MnO2负载量与MnOx/TiO2-Al2O3催化剂活性的关系;以含苯酚、喹啉和氨氮的模拟焦化废水为对象,在连续超临界水氧化装置上评价了该催化剂的性能。实验结果表明,MnOx/TiO2-Al2O3催化剂的最佳制备条件为:以硝酸锰溶液为浸渍液,MnO2负载量(质量分数)10%,120℃下干燥4h,500℃下焙烧2h。与MnOx催化剂相比,MnOx/TiO2-Al2O3催化剂具有较高的比表面积,并在超临界水氧化处理焦化废水过程中表现出了较好的活性。在100h的实验中,MnOx/TiO2-Al2O3催化剂表现出较好的稳定性。

Application of MnOx/TiO2-Al2O3 Catalyst to Supercritical Water Oxidation

MnOx/TiO2-Al2O3 catalyst was prepared by isochoric impregnation of manganese nitrate solution and TiO2-Al2O3 support.The obtained catalyst was characterized by means of DTG-MS,TPR,XRD and BET.Activity of the catalyst in oxidation of coking waste water containing phenol,quinoline and NH3-N was evaluated in a continuous supercritical water oxidation apparatus.Decomposition of MnOx/TiO2-Al2O3 catalyst precursor and effect of MnO2 content in the catalyst on its activity were studied.The prepared catalyst precursor was dried at 120 ℃ for 4 h and calcined at 500 ℃ for 2 h.The preferred MnO2 content in catalyst was 10%(mass fraction).The specific surface area of MnOx/TiO2-Al2O3 catalyst was larger than that of conventional catalyst containing solely of MnOx and its activity was higher.Performance of MnOx/TiO2-Al2O3 catalyst kept steady in supercritical water oxidation of coking waste water for 100 h.