CAJ | 학술논문

采用FTIR,XRD,XPS和TG-DTA等表征了一组具有不同组成的由沉淀-混合沉淀法制得的SO2-4/ZrO2-SiO2超强酸催化剂.由实验结果可知,催化剂的超强酸点可能是由于SO2-4基团与二元氧化物中的锆相互作用而产生的.与SO2-4/ZrO2催化剂不同的是,即使在650 ℃以上温度下焙烧的SO2-4/ZrO2-SiO2催化剂也是无定型的.800 ℃以上焙烧前体二元氧化物时,按照锆硅比的不同将出现两种不同的情况,硅锆比小于8时,其XRD谱图上出现属于四方晶型的二氧化锆的衍射峰;而当硅锆比大于8时,XRD谱图显示产生了一种新型的结晶体.研究结果表明,SO2-4基团与二元氧化物中Zr原子作用形成了酸性中心.
채용FTIR,XRD,XPS화TG-DTA등표정료일조구유불동조성적유침정-혼합침정법제득적SO2-4/ZrO2-SiO2초강산최화제.유실험결과가지,최화제적초강산점가능시유우SO2-4기단여이원양화물중적고상호작용이산생적.여SO2-4/ZrO2최화제불동적시,즉사재650 ℃이상온도하배소적SO2-4/ZrO2-SiO2최화제야시무정형적.800 ℃이상배소전체이원양화물시,안조고규비적불동장출현량충불동적정황,규고비소우8시,기XRD보도상출현속우사방정형적이양화고적연사봉;이당규고비대우8시,XRD보도현시산생료일충신형적결정체.연구결과표명,SO2-4기단여이원양화물중Zr원자작용형성료산성중심.
A series of SO2-4/ZrO2-SiO2 catalysts with different composition, which were prepared by a precipitating/mixing precipitate method, were characterized by FTIR, XRD, XPS and TG-DTA. Unlike SO2-4/ZrO2 catalyst, the SO2-4/ZrO2-SiO2 catalysts are usually amorphous even calcined at 650 ℃. When the precursor binary oxides were calcined above 800 ℃, two different types of XRD pattern appeared according to the ratio of SiO2 to ZrO2. As the ratio is below 8, the XRD patterns can be attributed to the tetragonal zirconia existed in catalysts as micro particles. Whereas, as the ratio is above 8, the XRD patterns show that a new type of crystal was formed. It is suggested that the interaction of SO2-4 group with Zr in binary oxide result in the forming of acid sites.