新型金屬有機(jī)框架復(fù)合納米材料的合成及其在光催化及電催化的應(yīng)用
發(fā)布時(shí)間：2018-12-12 06:50
【摘要】：針對(duì)金屬有機(jī)框架在各種領(lǐng)域中的應(yīng)用,對(duì)其光催化和電催化性能進(jìn)行研究。從光催化中的光催化氧化一氧化氮,到電催化中的燃料電池陰極氧還原反應(yīng),就大氣環(huán)境問(wèn)題,以及世界能源問(wèn)題展開研究。本文主要采用微波輔助合成的方法,合成了兩種新型的金屬有機(jī)框架催化劑。其中光催化劑在可見光照射下,考察了其在流動(dòng)相中對(duì)一氧化氮的光催化氧化去除活性。電催化劑在常溫環(huán)境下,考察了其在堿性體系中對(duì)氧氣的電催化氧還原反應(yīng)的活性和穩(wěn)定性,以及在甲醇體系中的穩(wěn)定性。期望通過(guò)這些研究,為環(huán)境、能源、化工、機(jī)動(dòng)車等提供高效的催化劑和先進(jìn)技術(shù)。(1)微波合成摻金的金屬有機(jī)骨架(Ti)及其可見光光催化氧化NO的研究采用微波輔助合成技術(shù),成功制備出了一種具有可見光光催化氧化去除一氧化氮活性的新型金屬有機(jī)框架NH_2-MIL-125(Ti)。通過(guò)浸漬還原法均勻負(fù)載金納米顆粒,獲得Au@NH_2-MIL-125(Ti),負(fù)載金納米顆粒后能顯著提高金屬有機(jī)框架NH_2-MIL-125(Ti)催化劑的光催化活性且具有優(yōu)良的穩(wěn)定性。金納米顆粒有利于提高光的捕獲能力,同時(shí)還能促進(jìn)光生電子的快速傳導(dǎo),從而降低光生電子與空穴的復(fù)合,提高光催化活性。(2)新型CNT/ZIF基多孔碳復(fù)合納米材料(Co-N-CNT)的合成及其在氧還原反應(yīng)中的應(yīng)用選用非貴金屬電催化劑,以鈷作為金屬活性位點(diǎn),為了增加導(dǎo)電性,以碳納米管作為連接,用以促進(jìn)電子傳遞。最終選用ZIF-67作為犧牲模版。用微波合成法制備CNT/ZIF-67,在氬氣下進(jìn)行高溫?zé)崽幚?制備出的Co-N-CNT-700催化劑顯示較好的電催化氧還原反應(yīng)(ORR)活性;制備的催化劑Co-N-CNT-700與商用20%Pt/C催化劑進(jìn)行電催化ORR活性、耐甲醇性及穩(wěn)定性對(duì)比,其活性均優(yōu)于商用20%Pt/C催化劑。通過(guò)研制開發(fā)新型催化劑和優(yōu)化催化材料,著重解決目前光催化氧化一氧化氮所存在的由于光利用率低、光生電子-空穴復(fù)合率高等因素造成的低效率,結(jié)合相關(guān)表征和動(dòng)力學(xué)測(cè)試,揭示了光催化氧化一氧化氮的機(jī)理和構(gòu)效關(guān)系。以及目前電催化氧還原反應(yīng)中存在的催化劑造價(jià)高、制備過(guò)程復(fù)雜、催化劑易中毒等因素造成的電催化劑利用率低的問(wèn)題,結(jié)合相關(guān)表征以及電化學(xué)測(cè)試,解釋了電催化氧還原反應(yīng)的機(jī)理。
[Abstract]:The photocatalytic and electrocatalytic properties of organometallic frames in various fields were studied. From photocatalytic oxidation of nitric oxide in photocatalysis to cathodic oxygen reduction of fuel cells in electrocatalysis, atmospheric environmental problems and world energy problems have been studied. In this paper, two new organometallic framework catalysts were synthesized by microwave-assisted synthesis. The photocatalytic oxidation of nitric oxide in mobile phase was investigated by photocatalyst under visible light irradiation. The activity and stability of electrocatalytic oxygen reduction reaction in alkaline system and the stability in methanol system were investigated under normal temperature. Looking forward to these studies for the environment, energy, chemicals, (1) Microwave-assisted synthesis of gold-doped organometallic (Ti) and its visible light catalytic oxidation of NO are studied by microwave assisted synthesis. A novel metal-organic framework (NH_2-MIL-125 (Ti).) with visible photocatalytic oxidation activity for removal of nitric oxide was successfully prepared. Au@NH_2-MIL-125 (Ti), was obtained by uniformly loading gold nanoparticles by impregnation reduction method. The photocatalytic activity of organometallic framework NH_2-MIL-125 (Ti) catalyst can be improved by loading gold nanoparticles and has good stability. Gold nanoparticles can improve the ability to capture light and accelerate the fast conduction of photogenerated electrons, thus reducing the combination of photogenerated electrons and holes. (2) Synthesis of new CNT/ZIF based porous carbon nanocomposite (Co-N-CNT) and its application in oxygen reduction reaction using non-noble metal electrocatalyst with cobalt as the active site. To increase electrical conductivity, carbon nanotubes are used as connections to facilitate electron transfer. Finally, ZIF-67 is chosen as the sacrificial template. CNT/ZIF-67, was prepared by microwave synthesis under high temperature heat treatment in argon. The prepared Co-N-CNT-700 catalyst showed good (ORR) activity in oxygen reduction reaction. Compared with the commercial 20%Pt/C catalyst, the prepared Co-N-CNT-700 catalyst was superior to the commercial 20%Pt/C catalyst in the electrocatalytic ORR activity, methanol tolerance and stability. By developing new catalysts and optimizing catalytic materials, the low efficiency caused by low photocatalytic oxidation of nitric oxide (no) and high photoelectron / hole recombination rate is solved. The mechanism and structure-activity relationship of photocatalytic oxidation of nitric oxide were revealed by correlation characterization and kinetic tests. And the problems of low utilization rate of electrocatalyst caused by high cost, complex preparation process and easy poisoning of catalyst in the current electrocatalytic oxygen reduction reaction, combined with related characterization and electrochemical test. The mechanism of electrocatalytic oxygen reduction is explained.
【學(xué)位授予單位】：上海師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O643.36
本文編號(hào)：2374124
[Abstract]:The photocatalytic and electrocatalytic properties of organometallic frames in various fields were studied. From photocatalytic oxidation of nitric oxide in photocatalysis to cathodic oxygen reduction of fuel cells in electrocatalysis, atmospheric environmental problems and world energy problems have been studied. In this paper, two new organometallic framework catalysts were synthesized by microwave-assisted synthesis. The photocatalytic oxidation of nitric oxide in mobile phase was investigated by photocatalyst under visible light irradiation. The activity and stability of electrocatalytic oxygen reduction reaction in alkaline system and the stability in methanol system were investigated under normal temperature. Looking forward to these studies for the environment, energy, chemicals, (1) Microwave-assisted synthesis of gold-doped organometallic (Ti) and its visible light catalytic oxidation of NO are studied by microwave assisted synthesis. A novel metal-organic framework (NH_2-MIL-125 (Ti).) with visible photocatalytic oxidation activity for removal of nitric oxide was successfully prepared. Au@NH_2-MIL-125 (Ti), was obtained by uniformly loading gold nanoparticles by impregnation reduction method. The photocatalytic activity of organometallic framework NH_2-MIL-125 (Ti) catalyst can be improved by loading gold nanoparticles and has good stability. Gold nanoparticles can improve the ability to capture light and accelerate the fast conduction of photogenerated electrons, thus reducing the combination of photogenerated electrons and holes. (2) Synthesis of new CNT/ZIF based porous carbon nanocomposite (Co-N-CNT) and its application in oxygen reduction reaction using non-noble metal electrocatalyst with cobalt as the active site. To increase electrical conductivity, carbon nanotubes are used as connections to facilitate electron transfer. Finally, ZIF-67 is chosen as the sacrificial template. CNT/ZIF-67, was prepared by microwave synthesis under high temperature heat treatment in argon. The prepared Co-N-CNT-700 catalyst showed good (ORR) activity in oxygen reduction reaction. Compared with the commercial 20%Pt/C catalyst, the prepared Co-N-CNT-700 catalyst was superior to the commercial 20%Pt/C catalyst in the electrocatalytic ORR activity, methanol tolerance and stability. By developing new catalysts and optimizing catalytic materials, the low efficiency caused by low photocatalytic oxidation of nitric oxide (no) and high photoelectron / hole recombination rate is solved. The mechanism and structure-activity relationship of photocatalytic oxidation of nitric oxide were revealed by correlation characterization and kinetic tests. And the problems of low utilization rate of electrocatalyst caused by high cost, complex preparation process and easy poisoning of catalyst in the current electrocatalytic oxygen reduction reaction, combined with related characterization and electrochemical test. The mechanism of electrocatalytic oxygen reduction is explained.
【學(xué)位授予單位】：上海師范大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O643.36
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 Xuemei Wang;Jianmin Chen;Tiantao Cheng;Renyi Zhang;Xinming Wang;;Particle number concentration, size distribution and chemical composition during haze and photochemical smog episodes in Shanghai[J];Journal of Environmental Sciences;2014年09期
，本文編號(hào)：2374124
本文鏈接：http://sikaile.net/kejilunwen/huaxue/2374124.html
最近更新
教材專著
