氮掺杂活性炭氧还原催化剂制备及效能评价

发布时间：2018-06-12 03:20

本文选题：微生物燃料电池 + 掺氮炭粉催化剂　；参考：《辽宁大学》2015年硕士论文

【摘要】：微生物燃料电池(Microbial fuel cell, MFC)是21世纪环境工程领域新兴的废水处理同步能源回收技术,能在胞外产电菌的作用下将有机废物中的化学能直接转化为电能,以空气中氧气作为氧化剂的MFC称之为空气阴极微生物燃料电池(Air-cathode Microbial Fuel Cell, ACMFC)。 ACMFC常使用铂炭作为阴极催化剂使其反应器加工成本较高。为降低ACMFC的成本,开发低成本高性能的阴极催化剂成为ACMFC的研究关键。本文选取普通活性炭(AC)和超级电容活性炭(SC)两种廉价炭粉,使用硝酸(Nitric acid),尿素(Carbamide)及碳酸铵(Ammonium carbonate)三种方法对炭粉进行掺氮处理。对掺氮前后的炭粉进行旋转圆盘电极(RDE)测试,结果表明掺氮处理后的炭粉的电子转移数均提高,并且掺氮炭粉AC的电子转移数高于炭粉SC,其中经硝酸处理后的碳粉的电子转移数最高,碳酸铵处理的炭粉次之,而经尿素处理的炭粉最小。采用X射线光电子能谱分析掺氮炭粉含氮官能团的变化,发现氮氧化物及吡啶型氮是影响催化活性的主要官能团。经尿素处理炭粉对pH(pH,5～11)适用范围更广。交流阻抗表明(EIS)掺氮后阴极内阻均减小,未掺氮炭粉AC阴极内阻低于未掺氮炭粉SC阴极,尿素处理后炭粉的阴极内阻低于碳酸铵及硝酸处理后炭粉的阴极。对各炭粉阴极的ACMFC产电性能研究发现,使用乙酸钠作为底物,掺氮前订,炭粉AC阴极的最大功率密度为1470mW/m2,略高于炭粉SC阴极1390mW/m2。经尿素处理后,两种炭粉阴极产电提升均最大,尿素掺杂炭粉SC的最大功率密度为1560mW/m2,较掺氮前最大功率密度提高12.2%；尿素掺杂炭粉AC的最大功率密度为1798mW/m2,较掺氮前提高22.3%,较尿素掺杂炭粉SC提高15.3%。通过对实际生活污水的产能分析得到,其产能规律与乙酸钠进水一致,其中经尿素掺氮炭粉对实际废水库伦效率及COD的除率均较高。对阴极催化剂的成本核算得出,炭粉AC经尿素掺氮后的单位产能所需成本是掺氮前的83.1%,是炭粉SC的15.4%。因此,经尿素处理的炭粉AC不仅能够降低成本,且能够获得更高的能量输出,在处理实际废水中具有更广阔的应用前景。在ACMFC反应器中运行6d的阴极,刮去生物膜后阴极性能提高,而运行15d和30d的阴极刮去生物膜阴极性能不变,可能是随着运行时间增加,阴极生物膜会逐渐进入催化层阻塞微孔。
[Abstract]:Microbial fuel cell (MFC) is a new technology of synchronous energy recovery for wastewater treatment in the field of environmental engineering in twenty-first Century. It can convert the chemical energy of organic waste into electric energy directly under the action of extracellular producing bacteria, and it is called the air cathode microbial fuel cell (Air-cathod) with the oxygen of air in the air as the MFC of the oxidizer. E Microbial Fuel Cell, ACMFC). ACMFC often uses platinum carbon as the cathode catalyst to make the reactor cost higher. In order to reduce the cost of ACMFC, developing low cost and high performance cathode catalyst is the key to the research of ACMFC. This paper selects two kinds of cheap carbon powder, ordinary activated carbon (AC) and super capacitor activated carbon (SC), using nitric acid (Nitric AC). ID), three methods, urea (Carbamide) and ammonium carbonate (Ammonium carbonate) were used to treat the carbon powder. The carbon powder before and after nitrogen was tested by rotating disk electrode (RDE). The results showed that the number of electron transfer of carbon powder after nitrogen treatment increased, and the electron transfer number of AC doped with nitrogen was higher than that of carbon powder SC, which was treated with nitric acid after nitric acid treatment. The electron transfer number of carbon powder is the highest, the carbon powder treated by ammonium carbonate is the second, and the carbon powder treated by urea is the smallest. X ray photoelectron spectroscopy is used to analyze the changes in nitrogen containing functional groups of nitrogen doped carbon powder. It is found that nitrogen oxides and pyridine nitrogen are the main functional groups affecting the catalytic activity. The application of carbamide treatment to pH (pH, 5~11) is more widely. The flow impedance showed that the internal resistance of the cathode decreased after EIS, and the internal resistance of the AC cathode was lower than that of the non carbon powder SC cathode. The cathodic resistance of the carbon powder after urea treatment was lower than that of the carbon powder after the treatment of ammonium carbonate and nitric acid after treatment. The study of the ACMFC production performance of the carbon powder cathode found that the sodium acetate was used as the substrate and the carbon powder was AC negative. The maximum maximum power density is 1470mW/m2, slightly higher than the carbon powder SC cathode 1390mW/m2. after urea treatment, the two carbon powder cathode production is the largest, the maximum power density of the urea doped carbon powder SC is 1560mW/m2, the maximum power density is 12.2% before the nitrogen doping, and the maximum power density of the urea doped carbon powder AC is 1798mW/m2, and it is higher than that before the nitrogen doping. 22.3%, compared with the urea doped carbon powder SC to improve the capacity of 15.3%. through the analysis of the capacity of actual domestic sewage, its productivity law is consistent with the influent of sodium acetate. The removal rate of Kulun efficiency and COD of the actual wastewater by the urea doped carbon powder is higher. The cost accounting of the cathode catalyst shows that the unit capacity of the carbon powder AC after the nitrogen is required for the production of the unit. It is 83.1% before nitrogen and 15.4%. of carbon powder SC. Therefore, the carbon powder AC treated by urea can not only reduce the cost, but also can obtain higher energy output. It has a wider application prospect in the treatment of actual wastewater. The cathode of 6D in the ACMFC reactor is run, the cathode performance is improved after the scraping of the biofilm, and the cathode scraper of 15d and 30d is run. The performance of the biofilm cathode remains unchanged. It may be that as the running time increases, the cathode biofilm will gradually enter the catalytic layer to block the micropores.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ426;TM911.45

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