脉冲放电协同Ag改性CeOx/γ-Al2O3催化剂对富氧条件下NOx的脱除
Pulsed discharge coordinated with Ag modified CeOx/γ-Al2O3 catalyst for NOx removal under the oxygen rich atmosphere
-
摘要: 随着机动车尾气中氮氧化物排放量的逐年增加，其对环境还有人体的危害也越来越大，为控制氮氧化物的排放,采用多针-板脉冲放电协同负载Ni、Co、Mn、Ce等金属氧物的复合型γ-Al2O3催化剂技术研究其在富氧条件下的脱硝效率，以及NO转化率，并使用Ag对γ-Al2O3催化剂进行相关改性制备出金属氧化物复合型催化剂，进而研究其脱硝率。结果表明：CeOx/γ-Al2O3催化剂的催化效果好于其他金属氧化物催化剂，其中脉冲放电协同CeOx/γ-Al2O3催化剂脱硝率为40.75%；不同负载量的Ce对催化剂活性影响也不同，协同负载量为1%的CeOx/γ-Al2O3催化剂最佳脱硝效率为48.89%，NO转化率达到67.33%；在Ag改性且Ag负载量为1%后，CeOx/γ-Al2O3催化剂其协同脉冲放电脱硝效率达到51.67%，对其BET表征后发现比表面积增加了3 m2?g-1，同时催化剂上NOx的还原活化位点增多。实验结果表明Ag改性CeOx/γ-Al2O3催化剂协同脉冲放电在富氧条件下可以有效提高NOx去除率，为下一步开发更高性能的催化剂提供了研究依据。Abstract: With the increasing of nitrogen oxides emissions from vehicle exhaust each year, more and more harmful effects occurred on the environment and human being. In order to control the nitrogen oxides emission, a type of multi-needle-plate pulse discharge method coordinated with the technology of γ-Al2O3 catalyst supported with metal (such as Ni, Co, Mn and Ce) oxides was used to study the denitrification and NO conversion under the condition of oxygen enrichments. A type of metal oxide composite catalyst was also prepared by modifying γ-Al2O3 with Ag. The results show that the CeOx/γ-Al2O3 catalyst has a better catalytic performance than other metal oxide catalysts, and the denitrification rate could reach 40.75% in coordination with the pulse discharge. The catalytic activity of CeOx/γ-Al2O3 catalyst depended on the loaded Ce content, and 1% Ce loading can result in the best denitrification rate of 48.89% for this catalyst with the NO conversion rate of 67.33%. For the CeOx/γ-Al2O3 catalyst modified with 1% Ag loading, its denitrification rate could reach 51.67% in coordination with the pulse discharge. The BET test for this catalyst showed that its specific surface area increased by 3 m2?g-1, and the activation sites on its surface for NOx reduction increased. We concluded that the Ag-modified CeOx/γ-Al2O3 catalyst in coordination with the pulse discharge can effectively improve the NOx removal rate under the condition of oxygen enrichment, which is helpful to further research on this type of catalyst with a high denitrification performance.
-
Key words:
- pulsed discharge /
- Ag modification /
- synergism /
- metal oxide catalyst
-
-
[1] 卢芳.大气中氮氧化物对生态环境的影响[J]. 青海师范大学学报（自然科学版）,2006(3):87-89 [2] 俞璐.氮氧化物对臭氧层的威胁[J]. 中国环境科学,2010,30(3):327-327 [3] 阮亿明.氮氧化物与环境[J]. 凉山大学学报,2004,6(3):34-36 [4] 张民.汽车尾气对人体健康的危害及其防治[J]. 职业与健康,2008,24(24):2728-2729 [5] 中华人民共和国环境保护部.2015年中国环境状况公报[R].2016 [6] 杨飏.氮氧化物减排技术与烟气脱硝工程[M]. 北京: 冶金工业出版社,2007 [7] 唐晓龙.低温选择性催化还原x技术及反应机理[M]. 北京: 冶金工业出版社,2007 [8] MA S M,ZHAO Y C,YANG J P .Research progress of pollutants removal from coal-fired flue gasusing non-thermal plasma[J].Renewable and Sustainable Energy Reviews,2017,67:791–810 10.1016/j.rser.2016.09.066 [9] 闫克平，李树然，冯卫强，等. 高电压环境工程应用研究关键技术问题分析及展望[J].高电压技术,2015,41(8):2528-2544 [10] 商克峰，李杰，吴彦. 非热等离子体脱硫脱氮技术的应用研究进展[J].中原工学院学报,2003,14(S1):52-53 [11] 王攀，谷文业，蔡忆昔，等.NTP协同 LKFMCO催化剂对柴油机NOx和碳烟排放的影响[J].内燃机工程,2016,37(3):18-22 [12] JUN X C, PAN K L, YU S J.Combined fast selective reduction using Mn-based catalystsandnonthermal plasma for NOx removal[J].Environmental Science & Pollutionearch,2017,24:21496–21508 10.1007/s11356-017-9785-8 [13] HUESO J L, COTRINO J, CABALLEROA A.Plasma catalysis with perovskite-type catalysts for the removal of NO and CH4 from combustion exhausts[J].Journal of Catalysis,2007,247:288-297 10.1016/j.jcat.2007.02.006 [14] 何俊文.多针-板脉冲放电协同g-Al2O3脱除模拟机车尾气中的NOx[D].赣州：江西理工大学，2017 [15] 董冰岩，黄尝伟，江小华，等. 脉冲放电协同负载型氧化物催化剂降解甲醛[J].环境工程学报,2015,9(10):4947-4952 [16] 任晓光，李富霞，李鹏.NiO-CuO/ZSM-5催化剂对催化裂化烟气的脱硫脱硝性能[J].[19] 孟凡会，常慧蓉，李忠.Ni-Mn/Al2O3催化剂在浆态床中CO甲烷化催化性能[J]. 化工学报,2014,65(8):2997-3003 [17] 刘彤，于琴琴，王卉，等. 等离子体与催化剂协同催化CH4选择性还原脱硝反应[J]. 催化学报,2011,32(9):1502-1507 [18] 董冰岩，施志勇，何俊文，等. 脉冲放电等离子体协同Mn/TiO2-分子筛、Fe/TiO2-分子筛、Cu/TiO2-分子筛催化剂降解甲醛[J]. 化工进展,2015,34(9):3337-3344 [19] 张亚通，王虎，李立，等.γ-Al2O3负载多金属复合催化剂选择性催化还原烟气脱硝[J].化工环保, 2015，35(6):645-650 [20] 姚小江，贡营涛，李红丽，等. 铈基催化剂用于NH3选择性催化还原NOx的研究进展[J]. 物理化学学报,2015,31(5):817-828 [21] JIANG N, HU J, LI J, et al.Plasma-catalytic degradation of benzene over Ag–Ce bimetallic oxide catalysts using hybrid surface/packed-bed discharge plasmas[J].Applied Catalysis B: Environmental,2016,184:355-363 10.1016/j.apcatb.2015.11.044 [22] BAO X, MALIK M A, NORTON D G, et al.Shielded sliding discharge-assisted hydrocarbon selective catalytic reduction of NOxover Ag/Al2O3 catalysts using diesel as a reductant[J].Plasma Chemistry and Plasma Processing,2014,34(4):825-836 10.1007/s11090-014-9551-3 -
点击查看大图
计量
- 文章访问数: 2032
- HTML全文浏览数: 1833
- PDF下载数: 126
- 施引文献: 0
下载:
