本文選題：核殼納米粒子 + 氨硼烷��； 參考：《江西師范大學(xué)》2015年碩士論文

【摘要】：近年來,氫氣作為全球公認(rèn)的清潔能源載體,備受關(guān)注和重視。發(fā)展安全高效的儲(chǔ)氫材料仍然是氫經(jīng)濟(jì)社會(huì)的最大挑戰(zhàn)之一。氨硼烷由于高儲(chǔ)氫量、環(huán)境友好性等優(yōu)點(diǎn)成為極具潛在應(yīng)用價(jià)值的儲(chǔ)氫材料之一。目前,氨硼烷水解反應(yīng)的催化劑大部分是單金屬、雙金屬或者三金屬,這些金屬納米催化劑由于直接裸露在反應(yīng)體系中會(huì)出現(xiàn)聚集現(xiàn)象而導(dǎo)致其活性降低,甚至失活。因此,尋求一種高效穩(wěn)定的催化劑成為目前研究的熱點(diǎn)。本文主要圍繞以二氧化硅為殼均勻包裹金屬納米粒子的制備、表征以及催化性能展開研究,主要內(nèi)容如下:在非離子表面活性劑壬基酚聚氧乙烯醚(NP-5)/環(huán)己烷反膠束體系中,以K2PtCl4為前驅(qū)體,合成了嵌入二氧化硅納米球中尺寸約為4 nm的超細(xì)Pt納米粒子(Pt@SiO2)。與單金屬Pt納米粒子和負(fù)載型Pt/SiO2納米粒子相比較,Pt@SiO2核殼納米催化劑在催化氨硼烷水解制氫過程中表現(xiàn)出了更優(yōu)的催化性能,其TOF值為158.6 mol H2(mol Pt min)-1,在已報(bào)道的Pt基催化劑中屬于比較高的值。經(jīng)過循環(huán)使用以及高溫處理測(cè)試,Pt@SiO2核殼納米結(jié)構(gòu)的形貌和催化活性都沒有明顯變化,表現(xiàn)出優(yōu)異的穩(wěn)定性。在反膠束微乳液體系中,以Co(NH3)6Cl3為前驅(qū)體,制備Co@SiO2核殼納米粒子。利用簡(jiǎn)單的化學(xué)浸漬法,采用氨硼烷作為還原劑,成功地一步原位還原制備Ag/Co@SiO2納米復(fù)合催化劑,同時(shí)催化氨硼烷水解制氫。其催化性能優(yōu)于單金屬Ag納米粒子,SiO2負(fù)載的Ag納米粒子(Ag/SiO2),單獨(dú)的Co@Si O2核殼納米粒子以及物理混合的Ag和Co@SiO2納米粒子。通過測(cè)試不同溫度下的催化活性,得出其反應(yīng)活化能為24.9 k J mol-1,較低于其他報(bào)道過的雙金屬催化劑的活化能值。常溫常壓下循環(huán)使用5次后,其催化性能沒有明顯的降低,表明了該催化劑具有較好的循環(huán)穩(wěn)定性。
[Abstract]:In recent years, hydrogen, as a globally recognized carrier of clean energy, has attracted much attention. The development of safe and efficient hydrogen storage materials remains one of the biggest challenges of hydrogen economy and society. Because of its high hydrogen storage capacity and environmental friendliness, aminoborane has become one of the potential hydrogen storage materials. At present, the catalysts for hydrolysis of ammonium-borane are mostly monometallic, bimetallic or trimetallic, and these metal nanocatalysts decrease or even deactivate due to the aggregation phenomenon of direct exposure in the reaction system. Therefore, the search for a high-efficient and stable catalyst has become the focus of research. In this paper, the preparation, characterization and catalytic properties of metal nanoparticles coated with silicon dioxide as shell are studied. The main contents are as follows: in Nonionic surfactant NP-5 / cyclohexane reverse micelle system, Ultrafine Pt nanoparticles with the size of about 4 nm have been synthesized by using K2PtCl4 as precursor and embedded in silica nanospheres. Compared with monometallic Pt nanoparticles and supported Pt/SiO2 nanocrystalline catalysts, the catalytic performance of PTB / SiO2 core-shell nanocrystalline catalysts is better than that of Pt nanoparticles and supported Pt/SiO2 nanoparticles in the process of hydrolysis of aminoborane to produce hydrogen. Its TOF value is 158.6 mol H2(mol Pt min-1, which is a relatively high value in the reported Pt based catalysts. The morphology and catalytic activity of Pt@ Sio _ 2 core-shell nanostructures have not changed obviously after recycling and high temperature treatment, showing excellent stability. Co@SiO2 core-shell nanoparticles were prepared by using Co(NH3)6Cl3 as precursor in reverse micelle microemulsion system. Ag/Co@SiO2 nanocomposite catalyst was successfully prepared by one step in situ reduction with aminoborane as reductant by a simple chemical impregnation method. At the same time, it catalysed hydrolysis of aminoborane to produce hydrogen. Its catalytic performance is superior to that of Ag / Sio _ 2-supported Ag nanoparticles, single Co@Si O _ 2 core-shell nanoparticles and physical mixed Ag and Co@SiO2 nanoparticles. The activation energy of the catalyst is 24.9 kJ mol-1, which is lower than that of other bimetallic catalysts. After 5 cycles at room temperature and atmospheric pressure, the catalytic performance of the catalyst was not obviously decreased, which indicated that the catalyst had better cycle stability.
【學(xué)位授予單位】：江西師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ116.2;O643.36

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 黃仁忠;楊文靜;劉柳;陳秀艷;;氨硼烷基化學(xué)儲(chǔ)氫材料[J];沈陽師范大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年03期

，

本文編號(hào)：1895384