| Ni2+取代对ZnTi-LDH选择性光氧化去除NO的性能增强 |
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| 引用本文： | 杜智华,杨娟,戴俊,冷冲冲,张鸽.Ni2+取代对ZnTi-LDH选择性光氧化去除NO的性能增强[J].化工学报,2022,73(11):4998-5010. |
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| 作者姓名： | 杜智华 杨娟 戴俊 冷冲冲 张鸽 |
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| 作者单位： | 1.河南理工大学安全科学与工程学院，河南 焦作 454003;2.煤炭安全生产与清洁高效利用省部共建协同创新中心，河南 焦作 454003 |
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| 基金项目： | 国家自然科学基金项目(52074103);河南省自然科学基金项目(202300410181);河南省科技攻关重点项目(222102320095);河南省高等学校重点科研项目(21A440008) |
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| 摘 要： | 以NiCl2·6H2O为镍源，采用水热法首次合成了不同Ni2+取代量的锌钛层状双金属氢氧化物(NiZnTi-LDH)，通过X射线衍射、透射电镜、低温氮吸附、X射线光电子能谱与紫外-可见漫反射等测试研究了Ni2+取代对ZnTi-LDH晶相结构、微观形貌、孔结构、表面氧空位与光吸收性能的影响。以NiZnTi-LDH为催化剂，分别考察了模拟太阳光与可见光照射下的NO光氧化消除性能。结果表明：Ni2+部分取代Zn2+可在ZnTi-LDH的能带结构中形成一新的中间能级，产生可见光响应，同时Ni取代可于ZnTi-LDH表面形成氧空位(OV)。可见光照射下，ZnTi-LDH无NO氧化活性，最优催化剂27% NiZnTi-LDH的NO去除率为52.1%，NO x 脱除选择性高达97.4%。模拟太阳光照射下，27% NiZnTi-LDH的NO光氧化去除率为64.8%，是ZnTi-LDH的2.76倍，NO x 脱除选择性可达96.9%，且NO生成量占总硝酸盐的95.6%。Ni2+取代及由此形成的OV不仅促进光生电荷分离，同时利于超氧自由基(·O)的生成，在增强NO消除性能的同时，抑制有毒NO2的产生，实现NO至NO的深度光氧化。
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| 关 键 词： | 锌钛LDH 镍取代 深度光氧化 一氧化氮 氧空位 性能增强 |
| 收稿时间： | 2022-06-29 |
Performance enhancement of selective photo-oxidation for NO removal on ZnTi-LDH by Ni2+ substitution |
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| Zhihua DU,Juan YANG,Jun DAI,Chongchong LENG,Ge ZHANG.Performance enhancement of selective photo-oxidation for NO removal on ZnTi-LDH by Ni2+ substitution[J].Journal of Chemical Industry and Engineering(China),2022,73(11):4998-5010. |
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| Authors: | Zhihua DU Juan YANG Jun DAI Chongchong LENG Ge ZHANG |
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| Affiliation: | 1.School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo 454003, Henan, China;2.State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization, Jiaozuo 454003, Henan, China |
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| Abstract: | Ni-substituted Zn-Ti layered double hydroxide (NiZnTi-LDH) with different Ni2+ substitution ratios were firstly synthesized by using NiCl2·6H2O as nickel source via hydrothermal method. The effects of Ni2+ substitution on the crystal phase, morphology, pore structure, surface oxygen vacancy and light absorption properties of ZnTi-LDH were investigated by X-ray diffraction, transmission electron microscopy, low temperature nitrogen adsorption, X-ray photoelectron spectroscopy and UV-visible diffuse reflectance. Using NiZnTi-LDH as catalyst, the photo-oxidation and elimination performance of NO under simulated sunlight and visible light irradiation were investigated respectively. The results showed that partial Ni2+ substitution for Zn2+ formed a new intermediate energy level in the band structure of ZnTi-LDH that consequently produced visible light response, meanwhile Ni2+ substitution generated oxygen vacancies (OV) on ZnTi-LDH surface. Under visible light irradiation, ZnTi-LDH had no NO oxidation activity, and the optimal 27% NiZnTi-LDH catalyst showed a NO removal rate of 52.1% with a De-NO x selectivity up to 97.4%. Under simulated solar light irradiation, 27% NiZnTi-LDH exhibited a NO photo-oxidation removal rate of 64.8% that was 2.76 times of ZnTi-LDH and De-NO x selectivity was 96.9%, meanwhile the produced NO accounted for 95.6% of total nitrate. Ni2+ substitution and the resulting OV not only promoted the separation of photogenerated carriers, but also facilitated the generation of superoxide radical (·O). As a result, the photo-oxidative activity of NO removal was enhanced and the production of toxic NO2 was effectively inhibited, consequently achieving deep photo-oxidation of NO to NO. |
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| Keywords: | ZnTi-LDH Ni2+-substitution deep photo-oxidation NO oxygen vacancy performance enhancement |
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