Effect of Preparation Methods on Activation of Catalysts BaNi0.2Mn0.8Al11O19-δ for Dimethyl Ether Combustion

Catalytic combustion of dimethyl ether （DME） over hexaaluminate catalyst BaNi0.2Mn0.8Al11O19-δ has been investigated. The catalysts were prepared with the sol-gel method and reverse microemulsion method respectively and characterized by thermogravimetry-differential thermal analysis, X-ray diffraction and transimission electron microscope. It was found that the formation of Mn, Ni modified hexaaluminate was a relatively slow process via two solid state reactions and spinel structure was a transition phase. At the same calcined temperature and time, the catalyst prepared with the reverse microemulsion method could form the hexaaluminate phase more easily than that prepared with the sol-gel method. The catalyst BaNi0.2Mn0.8Al11O19-δ prepared with the reverse micro-emulsion method appeared a plate-like morphology, while it appeared a needle-like morphology when using the sol-gel method. The catalytic activities of catalysts BaNi0.2Mn0.8Al11O19-δ prepared with two different methods for DME combustion were tested. It showed that catalyst prepared with the reverse microemulsion method had better catalytic activity, i.e. T10% of DME had decreased by 45℃, about 90% conversion of diemthyl ether at 380℃.

在 hexaaluminate 催化剂 BaNi_(0.2 )Mn_(0.8 )Al_(11 )O_ 上的暗淡乙醇醚(DME ) 的催化燃烧(19- δ) 被调查了。催化剂分别地与大音阶的第五音胶化方法和反向的微乳液方法被准备并且由 thermogravimetry 微分的热分析， X 射线衍射和 transimission 电子显微镜描绘了。这被发现 Mn 的形成，修改 hexaaluminate 是的镍一相对经由二固态反应法和尖晶石结构的慢过程是一个转变阶段。在一样的锻烧的温度和时间，与反向的微乳液方法准备的催化剂能比与大音阶的第五音胶化方法准备了更容易形成 hexaaluminate 阶段。催化剂 BaNi_(0.2 )Mn_(0.8 )Al_(11 )O_( 与反向的微乳液方法准备的 19- δ) 出现了像板的形态学，当它出现了时像针的形态学当使用大音阶的第五音胶化方法时。催化剂 BaNi_(0.2 )Mn_(0.8 )Al_(11 )O_ 的催化活(为 DME 燃烧与二个不同方法作好准备的 19- δ) 被测试。它显示出与反向的微乳液方法准备的那催化剂最好催化活， DME 的 i.e.T_(10%) 由 45 ° C 减少了，在 380 ° C 的 diemthyl 醚的大约 90% 变换。