本文選題：對氨基苯酚 + 加氫催化��； 參考：《天津工業(yè)大學(xué)》2017年碩士論文

【摘要】：苯胺類化合物是一類重要的有機(jī)化工中間體,廣泛應(yīng)用于燃料、醫(yī)藥、殺蟲劑和顯影劑等精細(xì)化工品的合成。目前工業(yè)上制取苯胺類化合物的主要方法是以相應(yīng)的硝基苯類化合物為原料,通過催化劑將硝基加氫還原為氨基來制備。其中,對硝基苯酚(4-NP)還原制備對氨基苯酚(4-AP)就是一個重要的代表性反應(yīng)。目前,這類反應(yīng)的高效催化劑主要是貴金屬材料。針對貴金屬的稀缺與高成本,為了提高貴金屬催化劑的利用率以及催化活性,本文主要制備了兩類負(fù)載型的貴金屬類催化劑,并研究它們在這個反應(yīng)中的催化性能,具體內(nèi)容如下:1.以γ-Fe_2O_3為核,包覆水熱碳構(gòu)成核/殼結(jié)構(gòu)的載體材料,再通過水熱碳層的吸附作用,吸附Pt離子,在不同溫度下對其進(jìn)行高溫焙燒制備一系列的Fe_2O_3@C-Pt-T催化劑。制備得到3-4 μm的殼/核結(jié)構(gòu)微球,外層水熱碳大約50-60 nm厚。通過SEM,TEM,XRD,EDX,ICP,XPS等表征手段對催化劑進(jìn)行表征和催化性能測試。實驗結(jié)果證明,在600℃焙燒的催化劑催化性能最高,能夠在6 min內(nèi)將溶液中的底物完全反應(yīng)。在催化劑的整體結(jié)構(gòu)中,y-Fe_2O_3核賦予催化劑磁性,因此在催化劑的回收時,僅需要施加一個額外的磁場,就可以簡單快速并且高回收率的將催化劑從反應(yīng)體系中回收,而水熱碳層賦予催化劑的吸附性,不僅在負(fù)載Pt顆粒時可以吸附Pt~(4+),而且可以在催化過程中吸附反應(yīng)底物,進(jìn)一步提高了催化劑的催化性能。外層負(fù)載的Pt顆粒是催化劑的催化活性中心,小尺寸,高分散性的Pt顆粒不僅提高了貴金屬的利用率,降低了成本,還進(jìn)一步提高了催化劑的催化性能。該催化劑還具有非常好的循環(huán)穩(wěn)定性,在循環(huán)反應(yīng)十次之后其催化性能未見明顯衰減。2.首先以低溫水熱法合成了具有完美棒狀結(jié)構(gòu)的ZnO納米材料,并用作催化劑的載體材料,利用ZnO的光響應(yīng)特性,在紫外光的誘導(dǎo)下,在ZnO表面氧化PtCl_4~(2-)離子為PtO_2,并且沉積在ZnO納米棒表面,合成PtO_2/Zn0催化劑。通過對紫外光照時間不同的控制,制備一系列PtC_2/ZnO-t催化劑。通過SEM,TEM,XRD,EDX,ICP,XPS等表征手段和催化性能測試后,實驗結(jié)果表明,在紫外光下照射30 min的PtO2/ZnO-30催化性能最高,而且紫外誘導(dǎo)法合成PtO_2催化劑相比傳統(tǒng)濕法制備的催化劑催化性能提高了2.3倍,而且與相對應(yīng)的Pt單質(zhì)催化劑對比,催化性能也提高了6倍。該催化劑還具有非常好的循環(huán)穩(wěn)定性,在循環(huán)使用十次之后其催化性能未見明顯衰減。作為一種簡單綠色高效的合成方法,紫外誘導(dǎo)法體現(xiàn)了其獨特的優(yōu)越性以及未來工業(yè)生產(chǎn)的巨大應(yīng)用潛力。
[Abstract]:Aniline compounds are a kind of important organic chemical intermediates, which are widely used in the synthesis of fine chemicals such as fuel, medicine, insecticide and developer. At present, the main method of preparing aniline compounds in industry is to prepare nitrobenzene compounds by hydrogenation of nitro compounds to amino groups by using the corresponding nitrobenzene compounds as raw materials. The preparation of p-aminophenol 4-APs by reduction of p-nitrophenol 4-NPs is an important representative reaction. At present, the main catalysts for this kind of reactions are precious metal materials. In view of the scarcity and high cost of precious metals, in order to improve the utilization and catalytic activity of noble metal catalysts, two kinds of supported noble metal catalysts were prepared and their catalytic properties in this reaction were studied. The details are as follows: 1. Using 緯 -Fe _ 2O _ 3 as core and coated with hydrothermal carbon to form a core / shell structure carrier material, Pt ion was adsorbed by hydrothermal carbon layer and calcined at different temperatures to prepare a series of Fe2O3C-Pt-T catalysts. Shell / core microspheres of 3-4 渭 m were prepared, and the outer hydrothermal carbon was about 50-60 nm thick. The catalyst was characterized and its catalytic performance was tested by means of SEMMA-TEMX / XRDX EDX / ICP / XPS and so on. The results show that the catalyst calcined at 600 鈩，

本文編號：2002113