本文選題：Cu-Ni納米晶 + 可控合成��； 參考：《東南大學(xué)》2017年碩士論文

【摘要】：由于可控合成雙金屬納米材料可應(yīng)用于非均相催化,低溫燃料電池技術(shù)等很多領(lǐng)域,其研究正成為是一個(gè)中要熱門的課題。相比于單金屬催化劑,雙金屬催化劑可以通過不同金屬之間電子轉(zhuǎn)移,局部協(xié)同環(huán)境,晶格張力,表面元素的分布有更多的機(jī)會(huì)改變其催化性能。本文通過控制包覆劑、反應(yīng)時(shí)間、溫度等因素,利用溶劑熱法合成不同形貌的Cu-Ni雙金屬納米品,考察了納米晶形成過程的不同因素以及形成機(jī)理。此外,還通過鄰二甲苯催化氧化實(shí)驗(yàn)來探究不同形貌的納米晶的催化活性。在Cu-Ni雙金屬納米晶制備過程中,利用聚乙烯吡咯烷酮(PVP)為包覆劑、苯胺為還原劑在苯甲醇溶液中進(jìn)行,可控合成出的六邊形納米片和納米線,它們形貌比較規(guī)整、分散性很好,具有高結(jié)晶度。在合成過程中發(fā)現(xiàn),當(dāng)PVP溶度為0.2 mM,即較低時(shí),最終得到的納米粒子為六邊形納米片;而當(dāng)PVP溶度升高到0.4 mM時(shí),最終得到的納米粒子為納米線。同時(shí),溫度也是一個(gè)比較重要的影響因素,當(dāng)溫度低于170 ℃時(shí)納米粒子無(wú)法形成;而當(dāng)溫度高于220 ℃時(shí),納米粒子的成核和生長(zhǎng)速度會(huì)急劇加快,造成最終納米粒子的聚合。在催化氧化實(shí)驗(yàn)中,通過三種方法制備不同的催化劑來比較Cu-Ni雙金屬納米晶的催化性能。實(shí)驗(yàn)表明,與傳統(tǒng)的浸漬法相比,超聲法制備催化劑對(duì)鄰二甲苯催化燃燒反應(yīng)表現(xiàn)出比浸漬法更好的活性,特別是活性相為Cu-Ni納米線的催化劑擁有最優(yōu)的活性。同時(shí)載體為介孔分子篩(MZSM-5)催化劑負(fù)載11 wt%的Cu-Ni納米線活性相表現(xiàn)出更優(yōu)的活性。通過比較T90的數(shù)值,可以發(fā)現(xiàn)納米線催化劑的溫度大約比浸漬法催化劑低40 ℃,比原位法催化劑低70 ℃。MZSM-5負(fù)載的納米線具有優(yōu)異的活性主要是超聲過程中催化劑會(huì)形成一種類似于榴蓮狀的表面結(jié)構(gòu),導(dǎo)致了催化劑活性要優(yōu)于浸漬法制備的催化劑。
[Abstract]:Due to the controllable synthesis of bimetallic nanomaterials can be used in heterogeneous catalysis, low-temperature fuel cell technology and many other fields, its research is becoming a hot topic. Compared with monometallic catalysts, bimetallic catalysts have more opportunities to change their catalytic performance through electron transfer between different metals, local synergistic environment, lattice tension and distribution of surface elements. In this paper, Cu-Ni bimetallic nanocrystals with different morphologies were synthesized by controlling the coating agent, reaction time and temperature. The different factors and formation mechanism of nanocrystalline formation were investigated. In addition, the catalytic activity of nanocrystals with different morphologies was investigated by catalytic oxidation of o-xylene. In the preparation of Cu-Ni bimetallic nanocrystals, hexagonal nanowires and nanowires were synthesized by using polyvinylpyrrolidone (PVP) as coating agent and aniline as reducing agent in benzol solution. High crystallinity. It was found that when the solubility of PVP was 0. 2 mm, the final nanoparticles were hexagonal nanoparticles, while when the solubility of PVP increased to 0. 4 mm, the final nanoparticles were nanowires. At the same time, temperature is also an important factor, when the temperature is below 170 鈩，

本文編號(hào)：1961695