銅基甲醛乙炔化催化劑活性銅物種的形成及炔化性能研究
發(fā)布時間:2018-05-25 19:02
本文選題:甲醛乙炔化 + 活性銅物種; 參考:《山西大學(xué)》2014年碩士論文
【摘要】:1,4-丁炔二醇是一種重要的有機化工原料,向下游延伸可得到1,4-丁二醇等一系列高附加值的重要化學(xué)品。工業(yè)上,合成1,4-丁炔二醇采用以CuO-Bi2O3為催化劑的甲醛乙炔化工藝。目前我國已建成了多套1,4-丁炔二醇裝置,但核心技術(shù)炔化催化劑一直被國外所壟斷,亟待研究開發(fā)具有我國自主知識產(chǎn)權(quán)的炔化催化劑。本工作采用共沉淀法制備了CuO-Bi2O3/SiO2-MgO炔化催化劑,對比研究了不同活化過程對CuO-Bi2O3/SiO2-MgO催化劑活性銅物種形成及炔化性能的影響;在此基礎(chǔ)上,進一步考察了CuO晶粒尺寸及CUO-Bi2O3間相互作用對無載體CuO-Bi2O3炔化催化劑在活化過程中活性銅物種形成及炔化性能的影響,探討了CuO存在形式及Bi203的助劑作用與催化劑炔化性能間的內(nèi)在關(guān)聯(lián)。主要研究結(jié)果如下:1、采用共沉淀法制備了CuO-Bi2O3/SiO2-MgO炔化催化劑,對比研究了催化劑先甲醛還原獲得Cu20,后在乙炔存在下活化(過程Ⅰ)和甲醛/乙炔同時存在下活化(過程Ⅱ)兩個過程中CuO物種的轉(zhuǎn)變規(guī)律。結(jié)果表明,經(jīng)過程Ⅱ活化的催化劑表現(xiàn)出高的炔化反應(yīng)性能,而經(jīng)過程Ⅰ活化后,催化劑炔化反應(yīng)性能較差。通過對過程Ⅰ中間物種Cu20存在形式的表征發(fā)現(xiàn),造成這一結(jié)果的原因可能是過程Ⅰ的甲醛還原導(dǎo)致Cu20晶粒尺寸長大,從而使炔化亞銅活性中心數(shù)量減少。2、除銅物種晶粒尺寸外,CuO與Bi2O3間相互作用也可能是影響催化劑炔化性能的重要因素。借鑒第一部分的研究結(jié)果與方法,以無載體的CuO-Bi2O3炔化催化劑為研究對象,通過研究具有不同CuO晶粒尺寸及CuO-Bi2O3間相互作用的CuO-Bi2O3催化劑在甲醛乙炔化活化過程中活性銅物種形成以及由此引起的催化劑炔化性能的變化規(guī)律,探討了CuO晶粒尺寸及CuO-Bi2O3間相互作用對催化劑炔化性能的影響。結(jié)果表明,除CuO晶粒尺寸外,CuO與Bi203間相互作用也是影響催化劑炔化性能的重要因素。CuO晶粒尺寸低于36 nm,CuO-Bi2O3b間具有適宜相互作用時,在甲醛乙炔活化過程中CuO被有效轉(zhuǎn)變?yōu)槿不瘉嗐~活性物種,表現(xiàn)出較高的炔化反應(yīng)性能。當CuO晶粒尺寸進一步增大,CuO-Bi2O3間表現(xiàn)出強相互作用,形成CuBi2O4固溶體時,阻礙了銅物種向銅炔化活性物種的轉(zhuǎn)變,導(dǎo)致催化劑炔化性能降低。
[Abstract]:1-butynediol is an important organic chemical raw material, and a series of important chemicals with high added value can be obtained by extending downstream. In the industrial synthesis of 1,4-butynediol, formaldehyde acetylene was synthesized by using CuO-Bi2O3 as catalyst. At present, many sets of 1 / 4-butynediol units have been built in China, but the core technology of acetylene catalyst has been monopolized by foreign countries, so it is urgent to research and develop acetylene catalyst with our own intellectual property rights. In this work, CuO-Bi2O3/SiO2-MgO catalyst was prepared by coprecipitation method, and the effects of different activation processes on the formation of active copper species and acetylene properties of CuO-Bi2O3/SiO2-MgO catalyst were studied. The effects of CuO grain size and CUO-Bi2O3 interaction on the formation of active copper species and the acetylene properties of unsupported CuO-Bi2O3 catalyst during activation were investigated. The relationship between the form of CuO and the auxiliaries of Bi203 and the catalytic activity of the catalyst was discussed. The main results are as follows: 1. CuO-Bi2O3/SiO2-MgO acetylene catalyst was prepared by coprecipitation method. The transformation of CuO species in the presence of acetylene (process I) and formaldehyde / acetylene (process II) in the presence of acetylene was studied. The results showed that the catalyst activated by Cheng 鈪,
本文編號:1934315
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