本文選題：稀土氧化物 + 水合肼��； 參考：《天津工業(yè)大學(xué)》2017年碩士論文

【摘要】：目前,環(huán)境和能源問題日益嚴(yán)重,氫能作為一種清潔高效的新能源而備受關(guān)注。水合肼(N_2H_4·H_2O)是一種含氫量高,且便于存儲運輸?shù)囊后w儲氫材料,研究發(fā)現(xiàn),水合肼在催化劑的作用下可以選擇性分解產(chǎn)生N2和H_2,有利于氫能的應(yīng)用和開發(fā)。本文采用液相共還原的方法制備了用于催化分解水合肼產(chǎn)氫的鑭、釹、鐠等元素氧化物摻雜鎳的納米催化劑。該方法以鎳和稀土元素的鹽為前驅(qū)物,硼氫化鈉為還原劑,在室溫下共還原得到Ni1-x-(REO)x催化劑(REO為稀土氧化物),并對制得的催化劑進(jìn)行水合肼催化分解試驗。(1)室溫條件下通過液相共還原方法制備出不同配比的Ni-Nd_2O_3納米顆粒,采用X射線衍射(XRD)、透射電鏡(TEM)、能譜分析(EDS)、X射線光電子能譜分析(XPS)對Ni-Nd_2O_3顆粒的形貌和組成進(jìn)行表征,考察了納米顆粒對水合肼的催化分解性能。結(jié)果表明,Nd_2O_3會對鎳的晶體結(jié)構(gòu)和形貌產(chǎn)生影響,提高催化劑的分散程度;在70℃的條件下,Ni0.94-(Nd_2O_3)0.06納米催化劑具有很好的水合肼的分解性能,氫氣選擇性為99%,轉(zhuǎn)化頻率TOF值為52.17h~(-1),重復(fù)試驗中催化劑的催化性能基本保持不變,具有很好的穩(wěn)定性;(2)室溫條件下通過液相共還原方法制備出不同配比的Ni-La2O3納米顆粒,采用XRD、TEM、EDS、XPS對Ni-La203顆粒的形貌和組成進(jìn)行表征,并考察了納米顆粒對水合肼的催化分解性能。研究發(fā)現(xiàn),La2O3會對鎳的晶體結(jié)構(gòu)和形貌產(chǎn)生影響,可以有效減小納米顆粒的顆粒粒徑;在70℃的條件下,Ni_(0.8)-(La_2O_3)_(0.2)納米催化劑具有最佳的水合肼分解性能,氫氣選擇性為95%,轉(zhuǎn)化頻率TOF值為61.76h~(-1) 7次重復(fù)催化試驗的結(jié)果表明該催化劑具有較高的穩(wěn)定性;(3)堿性環(huán)境可以提高水合肼分解反應(yīng)的選擇性。對反應(yīng)體系中NaOH的濃度進(jìn)行考察,研究發(fā)現(xiàn),在反應(yīng)體系中加入NaOH溶液可以提高水合肼分解反應(yīng)的H_2選擇性,且隨著NaOH濃度的增加,催化反應(yīng)的H_2選擇性逐漸升高,當(dāng)NaOH濃度增大到一定程度時,催化反應(yīng)的H_2選擇性不再隨之改變,在單獨加入NaOH進(jìn)行水合肼分解測試時,水合肼不能被分解,說明NaOH溶液在水合肼分解反應(yīng)中起到促進(jìn)劑的作用。
[Abstract]:At present, environmental and energy problems are becoming more and more serious. Hydrogen energy as a clean and efficient new energy has attracted much attention. It is found that hydrazine hydrate can selectively decompose to produce N _ 2 and H _ 2s _ 2 under the action of catalyst, which is beneficial to the application and development of hydrogen energy. In this paper, nanocrystalline catalysts doped with oxides of lanthanum, neodymium and praseodymium were prepared by liquid phase co-reduction for the catalytic decomposition of hydrogen from hydrazine hydrate. In this method, nickel and rare earth salt are used as precursors, sodium borohydride is used as reductant, The Ni1-x-(REO)x catalyst was prepared by co-reduction at room temperature. The prepared catalyst was prepared by hydrazine hydrate catalytic decomposition test. At room temperature, different proportions of Ni-Nd_2O_3 nanoparticles were prepared by liquid phase co-reduction. The morphology and composition of Ni-Nd_2O_3 particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The catalytic decomposition of hydrazine hydrate was investigated. The results showed that the effect of Sid _ 2O _ 3 on the crystal structure and morphology of nickel and the dispersion of the catalyst were improved, and the nanometer catalyst Ni0.94-Nd2O30.06 had good decomposition performance of hydrazine hydrate at 70 鈩，

本文編號：1983898