【摘要】：氫氣是一種清潔、有效的、可循環(huán)利用的物質(zhì),可以高效的轉(zhuǎn)變?yōu)榭衫玫挠行芏划a(chǎn)生環(huán)境污染。在制氫的眾多方法中,電解水制氫是目前最簡(jiǎn)便,最廉價(jià),最潔凈的制備方法,但由于析氫過(guò)電位的存在使得能耗增加。高效的析氫電極材料應(yīng)該具有導(dǎo)電性好,析氫過(guò)電位低,電催化活性高以及電化學(xué)穩(wěn)定性好等特點(diǎn)。為了提高陰極的電催化析氫活性,通常對(duì)電極表面進(jìn)行設(shè)計(jì)、修飾,利用具有催化活性的催化劑修飾電極表面。Pt催化劑(Pt/C)被認(rèn)為是目前催化效果最好的析氫反應(yīng)催化劑,但成本高以及儲(chǔ)量少限制了Pt催化劑的廣泛應(yīng)用。因此,非Pt陰極催化劑的研究越來(lái)越得到人們的關(guān)注。針對(duì)鉑基催化劑的缺點(diǎn),本論文制備了氧化鈷/氮摻雜石墨烯和碳化物/碳兩種非鉑復(fù)合催化劑。1)以石墨烯為載體,采用微波輔助乙二醇還原法在石墨烯表面沉積納米氧化鈷顆粒,而后將其與三聚氰胺混和均勻,在N2氣氛下在不同溫度下熱處理。結(jié)果表明,在600℃條件下制備的樣品中CoO顆粒均勻地分布在褶皺的石墨烯表面,石墨烯的含氮量為8.6%,并且以其做催化劑的催化析氫反應(yīng)活性最高。由Tafel曲線獲得的動(dòng)力學(xué)參數(shù)可知其具有小的起始電位、小的Tafel斜率和大的交換電流密度,并具有高的電化學(xué)穩(wěn)定性,是一種有效的催化析氫反應(yīng)的非鉑催化劑,它比以相同的方法制備的以傳統(tǒng)碳黑(XC-72)為載體的氧化鈷/氮摻雜碳有更高的催化析氫反應(yīng)活性。2)采用真空微蒸發(fā)鍍法在870℃條件下加熱傳統(tǒng)碳黑(XC-72)和金屬鉬粉的混合粉末,成功在碳黑顆粒表面沉積碳化鉬。結(jié)果表明,得到的樣品是以Mo2C層包裹在碳黑顆粒表面的核殼結(jié)構(gòu),碳既作為載體材料,同時(shí)又作為合成復(fù)合材料的碳源。由Tafel曲線獲得的動(dòng)力學(xué)參數(shù)表明Mo2C/C復(fù)合催化劑具有較高的催化析氫反應(yīng)活性和穩(wěn)定性。
[Abstract]:Hydrogen is a clean, efficient, recyclable substance that can be efficiently converted to usable without environmental pollution. Among the many methods of hydrogen production, electrolytic water is the most convenient, cheapest and cleanest preparation method at present, but the energy consumption is increased due to the existence of hydrogen evolution overpotential. High efficiency hydrogen evolution electrode materials should have good conductivity, low hydrogen evolution overpotential, high electrocatalytic activity and good electrochemical stability. In order to improve the electrocatalytic hydrogen evolution activity of the cathode, the surface of the electrode is usually designed and modified, and the surface of the electrode is modified with the catalyst with catalytic activity. Pt catalyst (Pt/C) is considered to be the best catalyst for hydrogen evolution at present. However, high cost and less reserves limit the wide application of Pt catalysts. Therefore, the research of non-Pt cathode catalyst has been paid more and more attention. In view of the shortcomings of platin-based catalysts, two kinds of non-platinum composite catalysts, cobalt oxide / nitrogen doped graphene and carbides / carbon, were prepared in this paper. Nanocrystalline cobalt oxide particles were deposited on the surface of graphene by microwave-assisted ethylene glycol reduction method, and then mixed with melamine and heat treated at different temperatures in N2 atmosphere. The results showed that the CoO particles were uniformly distributed on the surface of folded graphene at 600 鈩，

本文編號(hào)：2281015