本文關(guān)鍵詞： 層狀雙金屬氫氧化物 復(fù)合金屬氧化物 薄膜 結(jié)構(gòu)化催化劑 催化氧化　出處：《北京化工大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：近年來(lái),新型薄膜催化劑的設(shè)計(jì)合成已成為催化研究領(lǐng)域的熱點(diǎn)之一。催化氧化反應(yīng)是一類(lèi)重要的化學(xué)反應(yīng),其中烴類(lèi)的氧化和醇類(lèi)的氧化現(xiàn)代催化工業(yè)生產(chǎn)中占據(jù)十分重要的地位,代表反應(yīng)有苯甲醇的氧化和乙苯的氧化。苯甲醇和乙苯都是重要的化工原料,而且其氧化產(chǎn)物苯甲醛和苯乙酮具有廣泛的應(yīng)用價(jià)值。本文采用氨原位合成法在陽(yáng)極氧化鋁基片上制備了Co-M-Al三元層狀雙金屬氫氧化物(LDH)薄膜,再經(jīng)高溫焙燒合成了相應(yīng)的復(fù)合金屬氧化物薄膜。以苯甲醇和乙苯的氧化為探針?lè)磻?yīng),考察了三元LDH薄膜及其復(fù)合金屬氧化物薄膜的選擇性氧化性能,并探討了薄膜的組成及表面結(jié)構(gòu)與催化性能之間的關(guān)系。主要研究?jī)?nèi)容如下：(一)在陽(yáng)極氧化鋁基片上,以氨水-硝酸銨為沉淀劑,原位合成了CoNiAl三元層狀雙金屬氫氧化物(LDH)薄膜；經(jīng)500℃高溫焙燒后得到CoNiAl-MMO薄膜。對(duì)所得薄膜催化劑進(jìn)行了結(jié)構(gòu)、組成及表面形貌表征,結(jié)果表明CoNiAl-MMO薄膜是由多種尖晶石固體溶液組成(C0304,CoAl2O4, NiAl2O4和NiCo2O4),其表面化學(xué)組成均勻,呈均勻的多孔網(wǎng)狀表面結(jié)構(gòu)。將CoNiAl-LDH(MMO)薄膜應(yīng)用于苯甲醇的催化氧化反應(yīng),結(jié)果表明與三元粉體催化劑和二元薄膜催化劑相比,CoNiAl-MMO薄膜催化劑表現(xiàn)出顯著提高的催化活性,室溫反應(yīng)條件下,轉(zhuǎn)化率可達(dá)29.3%,是CoNiAl-MMO粉體催化劑的2.44倍,CoAl-MMO二元薄膜催化劑的1.66倍。此外,CoNiAl-LDH薄膜催化劑的轉(zhuǎn)化率可達(dá)14.6%,是CoNiAl-LDH粉體的3.11倍,基于獨(dú)特CoNiAl-MMO表面組成和結(jié)構(gòu),其顯著提高的催化活性與活性物種鈷和鎳之間的強(qiáng)相互作用和多孔的表面結(jié)構(gòu)密切相關(guān)。(二)采用原位生長(zhǎng)技術(shù)和高溫焙燒技術(shù)相結(jié)合法制備了三元鈷錳復(fù)合金屬氧化物薄膜。采用XRD、SEM和TPR等表征手段對(duì)薄膜的組成和結(jié)構(gòu)進(jìn)行了分析,以乙苯氧化反應(yīng)為探針?lè)磻?yīng),研究了不同配比氧化物薄膜材料的催化性能以及催化條件對(duì)乙苯催化氧化反應(yīng)的影響。結(jié)果發(fā)現(xiàn):[Mn2+]/[Co2++Mn2+]為0.50時(shí)復(fù)合金屬氧化物薄膜催化劑顯示出最高的的催化乙苯氧化活性,這主要是歸因于其高的比表面、高分散可接近的活性物種及其相互相協(xié)同。
[Abstract]:In recent years, the design and synthesis of novel thin-film catalysts have become one of the hot spots in the field of catalytic research. Catalytic oxidation is an important chemical reaction. The oxidation of hydrocarbons and alcohols occupies a very important position in the modern catalytic industrial production, representing the oxidation of benzyl alcohol and ethylbenzene. Benzyl alcohol and ethylbenzene are important chemical raw materials. The oxidation products of benzaldehyde and acetophenone have wide application value. In this paper, Co-M-Al ternary layered bimetallic hydroxide (Co-M-Al) was prepared on anodic alumina substrate by in situ synthesis of ammonia. Film. Then the corresponding composite metal oxide films were synthesized by calcination at high temperature. The selective oxidation properties of ternary LDH films and their composite metal oxide films were investigated using the oxidation of benzyl alcohol and ethylbenzene as probes. The relationship between the composition, surface structure and catalytic performance of the film was discussed. The main contents are as follows: (1) on anodic aluminum oxide substrate, ammonia and ammonium nitrate are used as precipitators. CoNiAl ternary layered bimetallic hydroxide (CoNiAl) thin films were synthesized in situ. CoNiAl-MMO films were prepared by calcination at 500 鈩，

本文編號(hào)：1486296