摘要
采用共混法制备了Ti-Ce-Zr-Ox复合脱硝催化剂TiCe0.1Zr0.1O2.4,运用X射线衍射、氮气物理吸附、扫描电镜等表征手段,分别对该催化剂的晶型、表面积、孔分布及结构形貌进行了分析,同时考察了反应温度、空速、水蒸气和SO2对该催化剂NH3选择性催化还原NO的影响。结果表明,TiCe0.1Zr0.1O2.4催化的高活性温度窗口为200～350℃,在此区间内,NO的转化率均大于70%,在300℃时NO转化率达最高值,为92.70%;在TiCe0.1Zr0.1O2.4的单独催化下,随着空速的增加,NO最高转化率有所下降,且空速达到10 000 h-1左右后,NO最高转化率的出现温度向高温区偏移,除5 000 h-1外,在低温区域(150～300℃)随着空速的增加NO转化率均明显下降,而在高温区域(350～450℃)下降幅度均基本相对减小;单独通入SO2后,TiCe0.1Zr0.1O2.4在低于350℃时的催化活性得到了不同程度的提高,300℃时的NO转化率提高到了98.23%,单独通入水蒸气后,在150～400℃时TiCe0.1Zr0.1O2.4的催化活性大幅度下降,300℃时的NO转化率仅为47.43%,同时通入水蒸气和SO2后,在100～250℃时的NO转化率仅为1%～3%,到300℃时NO转化率恢复至74%左右,350℃时NO转化率达到最高值,为76.11%。
Series of Ti-Ce-Zr-Ox catalytic complex oxides were prepared by chemical blend for selective catalytic reduction（SCR） of NO.The crystal form,pore structure and crystalline morphology of the catalysts were characterized by X-ray diffraction（XRD）,N2 physical adsorption（BET） and scanning electron microscope（SEM） respectively;the effect of temperature,space velocity,H2O vapor and SO2 on NH3-SCR of NO was also investigated.Results showed that TiCe0.1Zr0.1O2.4 complex catalysts had high activity in the broad temperature range of 200-350 ℃,the NO conversion rate could maintain more than 70%.The catalyst achieved the highest SCR capacity at 300 ℃ with the corresponding NO conversion rate was 92.70%.The maximum NO conversion rate,which decreased with increasing space velocity was transferred to high temperature direction at space velocity of 10 000 h-1.Higher space velocity could decrease NO conversion obviously in low temperature zone,while the tendency was not obvious in high temperature zone.The presence of SO2 increased the catalyst activity significantly when the temperature was below 350 ℃ and the maximum NO conversion rate could reach to 98.23%.H2O vapor could inhibit the activity of catalyst in 150-400 ℃,the maximum NO conversion rate only reach at 47.43%.The presence of both H2O and SO2 could poisoned the catalyst in low temperature（100-250 ℃） with NO conversion rate ranged 1%-3%,the activity of the catalyst was recovered at 300 ℃ and optimized at 350 ℃,then the NO conversion rate achieved 76.11%.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2011年第1期12-16,共5页
Environmental Pollution & Control
基金
国家"863计划"项目(No.2009AA05Z313)
国家自然科学基金资助项目(No.50872052)
