本文選題：高嶺土 + 丙烷��； 參考：《內(nèi)蒙古師范大學(xué)》2017年碩士論文

【摘要】：隨著科技的快速發(fā)展,天然粘土資源的研發(fā)和利用成為國內(nèi)外科研應(yīng)用領(lǐng)域的前沿課題。其應(yīng)用研究水平成為影響一個國家科技水平發(fā)展的重要方面。高嶺土是一種重要的非金屬礦產(chǎn),它的主要成分為高嶺石族礦物,由Si-O四面體和Al-O八面體構(gòu)成層狀結(jié)構(gòu),是質(zhì)地純凈的細(xì)粒粘土,具有良好的可塑性、吸附性、易分散性、高白度和優(yōu)良的電絕緣性,目前被廣泛應(yīng)用于化工、環(huán)保、農(nóng)業(yè)、建筑等領(lǐng)域。內(nèi)蒙古自治區(qū)高嶺土資源豐富,價廉易得,將高嶺土改性可以得到具有一定孔結(jié)構(gòu)和高比表面積的材料,用于新型多相催化領(lǐng)域,是很好的催化劑及催化劑載體,對高嶺土資源的綜合利用具有重要意義。丙烯是石油化工基礎(chǔ)原料之一。隨著聚丙烯腈、丙烯醛及丙烯酸等丙烯下游產(chǎn)品需求量的快速增加,全球丙烯需求量也快速增長。傳統(tǒng)丙烯制備方法難以滿足需求。丙烷氧化脫氫制丙烯具有巨大的經(jīng)濟(jì)應(yīng)用前景,已經(jīng)成為催化領(lǐng)域研究的熱點(diǎn)。但在有氧條件下,丙烯易深度氧化,丙烯選擇性不理想。因此,制備穩(wěn)定且具有低溫高丙烯選擇性的催化劑是其研究關(guān)鍵。本研究采用介孔改性-浸漬法和共沉淀-焙燒法,制備高嶺土負(fù)載金屬氧化物催化劑,并進(jìn)行XRD,N_2吸附脫附,H_2-TPR,NH_3-TPD,XPS和電導(dǎo)性能等表征,優(yōu)化其丙烷氧化脫氫制丙烯催化性能,探究其催化性能的影響因素。1.將200目高嶺土用硫酸回流酸化,再加P123改性,550℃焙燒,制備孔道較均一的介孔改性高嶺土,比表面積389.4 m~2/g。2.采用浸漬法制備了V_2O_5/改性高嶺土系列催化劑。研究表明,該系列催化劑表面存在弱酸性位;改性高嶺土為p型半導(dǎo)體,負(fù)載V_2O_5催化劑為n型半導(dǎo)體;負(fù)載5%V_2O_5催化劑表面V5+較多;隨晶格氧含量增加,丙烯選擇性提高,600℃催化性能最佳:丙烷轉(zhuǎn)化率28.11%,丙烯選擇性62.38%。3.采用浸漬法制備NiO/改性高嶺土催化劑。研究表明,隨鎳負(fù)載量增加,催化劑電導(dǎo)類型保持p型半導(dǎo)體。NiO負(fù)載7.5%的催化劑低溫丙烷氧化脫氫制丙烯性能最好:450℃丙烷轉(zhuǎn)化率18.20%、丙烯選擇性49.80%。4.通過共沉淀-焙燒法制備了Ni-Al-O/高嶺土和Ni-Cr-O/高嶺土復(fù)合氧化物系列催化劑。10%Ni-Al-O/高嶺土復(fù)合氧化物催化劑在反應(yīng)溫度為525℃時丙烷轉(zhuǎn)化率19.88%,丙烯選擇性47.71%。10%Ni-Cr-O/高嶺土復(fù)合氧化物催化劑,在450℃時丙烷轉(zhuǎn)化率22.98%,丙烯選擇性44.50%。
[Abstract]:With the rapid development of science and technology, the research and utilization of natural clay resources has become a frontier subject in the field of scientific research and application at home and abroad. Its applied research level has become an important aspect that affects the development of a country's science and technology level. Kaolin is an important nonmetallic mineral, its main composition is kaolinite group mineral, which is composed of Si-O tetrahedron and Al-O octahedron. It is a pure fine clay with good plasticity, adsorption and dispersibility. High whiteness and excellent electrical insulation are widely used in chemical industry, environmental protection, agriculture, construction and other fields. Kaolin in Inner Mongolia Autonomous region is rich in resources and cheap and easy to obtain. By modifying kaolin, materials with certain pore structure and high specific surface area can be obtained, which can be used in the field of new heterogeneous catalysis, and it is a good catalyst and catalyst carrier. It is of great significance for comprehensive utilization of kaolin resources. Propylene is one of the basic raw materials in petrochemical industry. With the rapid increase of demand for downstream products such as polyacrylonitrile, acrolein and acrylic acid, the global demand for propylene is also increasing rapidly. The traditional propene preparation method is difficult to meet the demand. Oxidative dehydrogenation of propane to propylene has a great economic application prospect and has become a hot spot in the field of catalysis. However, under aerobic conditions, propylene is easy to be oxidized in depth, and the selectivity of propylene is not ideal. Therefore, the preparation of stable catalyst with low temperature and high propylene selectivity is the key to its research. In this study, kaolin supported metal oxide catalysts were prepared by mesoporous modification-impregnation method and coprecipitation-roasting method, and their catalytic properties were optimized by means of XRD- N2 adsorptive desorption, H2-TPRN NH3-TPD-XPS, conductivity, etc, to optimize their catalytic properties for oxidative dehydrogenation of propane to propylene. Explore the influence factors of its catalytic performance. 1. The mesoporous kaolin with homogeneous pore channels was prepared by refluxing and acidizing with sulfuric acid and calcination at 550 鈩，

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