铜钛基氧化物的制备及其催化氨选择性还原NO的研究

更新时间:2023-05-21 15:24:23 阅读: 评论:0

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密  级  公  开
孙膑兵法铜钛基氧化物的制备及其催化氨选择性还原
中国10大元帅
NO的研究
申请人:  张天瑞
对皮肤好的食物
学号:  2151119
培养单位:  化学化工与材料学院
学科专业:  无机化学
研究方向:  基于纳米结构的传感与催化材料妈妈眼中的我
指导教师:  朱宇君教授
从动轮完成日期:  2018年11月30日
中文摘要
氮氧化物(NO x)作为大气主要污染物之一,给人类健康和环境带来许多危害。因此,如何有效地消除NO x的排放已经成为全球科学家关注的问题。NH3选择性催化还原(NH3-SCR)被认为是最有效的消除燃煤电厂、工业锅炉等固定源NO x 排放的方法。尽管V2O5-WO3(MoO3)/TiO2作为一种商
植树看图写话一年级把子肉做法业催化剂已经应用于大型燃煤电厂烟气脱硝,但仍然存在操作温度窗口狭窄(300-400 o C),V2O5具有生物毒性,在高温时SO2容易氧化成SO3等问题。因此,本文通过在Ni-Ti和Ce-Ti体系中掺入适量的Cu来调变催化剂的氧化还原性和表面酸性,从而获得高活性、宽活性窗口的NH3-SCR脱硝催化剂。
采用溶胶凝胶法分别制备出了一系列Cu m Ni0.1-m TiO x(m = 0,0.01,0.015,0.02,0.03和0.1)和Cu m Ce0.1-m TiO x(m = 0,0.005,0.01,0.02,0.03和0.1)催化剂。并通过XRD、H2-TPR、NH3-TPD、XPS和in situ DRIFTS等表征探究Cu的掺入对催化剂结构和性能的影响。结果表明:Cu的掺入提高了催化剂的低温活性。Cu0.015Ni0.085TiO x催化剂在空速为40 000 h-1温度在205-425 o C范围内具有优异的活性(> 90%的NO转化率)。Cu0.01Ce0.09TiO x催化剂在40 000 h-1空速下在170-425 o C 展现了出色的活性(> 90%的NO转化率)。通过in situ DRIFTS研究发现Ni0.1TiO x 和Cu0.015Ni0.085TiO x催化剂,Ce0.1TiO x和Cu0.01Ce0.09TiO x催化剂的NH3-SCR反应主要通过表面吸附的NO x和NH3物种之间进行,遵循L-H反应机理。
关键词:氮氧化物;氨选择性催化还原;铜添加的影响;原位红外
I
Abstract
As one of the main air pollutants, nitrogen oxides (NO x) are harmful to the health of human and the environment. Thus, how to eliminate the emission of NO x effectively has become the concerned problem for the scientists all over the world. Among the way of removing NO x, lective catalytic reduction by NH3 (NH3-SCR) is considered as an efficient technique to remove NO x emissions which come mainly from the stationary sources such as coal-fired power plants, industrial boilers and so on. Though V2O5-WO3(MoO3)/TiO2 as a commercial catalyst has been ud for denitrification of flue gas in large coal-fired power plants, there are still many disadvantages to be resolved such as the narrow operation temperature window (300-400 o C), high conversion of SO2 to SO3 at high temperature and the biotoxicity of V2O5 for human and environment. Thus, the oxidability and the surface acidity were modulated by doping proper Cu in the system of Ni-Ti and Ce-Ti, which obtained the catalysts of NH3-SCR for denitrification with high catalytic activity and broad temperature window.
A ries of Cu m Ni0.1-m TiO x (m = 0, 0.01, 0.015, 0.02, 0.03 and 0.1) and Cu m Ce0.1-m TiO x (m = 0, 0.005, 0.01, 0.02, 0.03 and 0.1) catalysts were synthesized by the sol-gel method. Various characterizations including XRD, H2-TPR, NH3-TPD, XPS and in situ DRIFTS are ud to investigate the effect of Cu doping on the structure and properties of the catalyst. The results sugges
t that the doping of Cu increa the low-temperature activity of the catalysts. The Cu0.015Ni0.085TiO x catalyst shows excellent performance (NO conversion > 90%) at the temperatre range of 205-425 o C at GHSV of 40 000 h-1. In addition, the Cu0.01Ce0.09TiO x catalyst exhibits superior performance at the temperatre range of 170-425 o C (NO conversion > 90%) at GHSV of 40 000 h-1. In situ DRIFTS results indicate that the NH3-SCR reaction for Ni0.1TiO x and Cu0.015Ni0.085TiO x catalysts as well as Ce0.1TiO x and Cu0.01Ce0.09TiO x catalysts mainly proceed through between the surface adsorbed NH3 species and the surface absorbed nitrogen oxides,
唐睢不辱使命II

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标签:催化剂   催化   掺入   活性   选择性   氧化   表面
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