硅酸盐学报

焙烧气氛对V-Mo-P/TiO₂催化还原脱硝性能的影响

PDF下载

吴雪莲 ¹ , 程会 ¹ , 余通 ¹ , 张昭军 ¹ , 王琪 ¹ , 魏凤玉 ¹ , 王梦瑜 ²

硅酸盐学报 | 研究论文 2025,53(7): 1952-1961

收起

硅酸盐学报 |研究论文 2025 , 53 (7) : 1952 -1961

焙烧气氛对V-Mo-P/TiO₂催化还原脱硝性能的影响

全屏

吴雪莲¹, 程会¹, 余通¹, 张昭军¹, 王琪¹, 魏凤玉¹, 王梦瑜²

作者信息

^1．合肥工业大学化学与化工学院，高值催化转化与反应工程安徽省重点实验室，合肥 230009

^2．合肥中亚环保科技有限公司，合肥 230051

通讯作者:

王琪（1978—），男，博士，副教授。

作者简介:

吴雪莲（1998—），女，硕士研究生。

Effect of Calcination Atmosphere on Catalytic Reduction Denitrification Performance of V-Mo-P/TiO₂

Xuelian WU¹, Hui CHENG¹, Tong YU¹, Zhaojun ZHANG¹, Qi WANG¹, Fengyu WEI¹, Mengyu WANG²

Affiliations

^1.School of Chemistry and Chemical Engineering, Anhui Province Key Laboratory of Value-Added Catalytic Conversion and Reaction Engineering, Hefei 230009, China

^2.Hefei Zhongya Environmental Protection Technology Co. Ltd., Hefei 230051, China

Corresponding Author:

WANG Qi (1978-), male, Ph.D., Associate Professor. E-mail: wangqi@hfut.edu.cn

WU Xuelian (1998-), female, Master candidate. E-mail: 2102602164@qq.com

出版时间: 2025-07-20 doi: 10.14062/j.issn.0454-5648.20240657

文章导航

摘要

收起

为探究不同性质的气体对V-Mo-P/TiO₂催化剂催化活性的影响，采用浸渍-焙烧法制备了V-Mo-P/TiO₂催化剂，考察了空气、氮气和氢气3种焙烧氛围对脱硝活性的作用，并对3种气氛焙烧催化剂进行了表征。结果表明：在空气氛围中焙烧的催化剂通过提高V⁵⁺含量的占比，进一步增加活性组分聚合钒的含量，来提高其氧化还原能力；通过促进催化剂表面形成V⁵⁺-OH结构来提高B酸酸性位点数量，这两者均能提高催化剂表面对NH₃吸附并活化，使其再与催化剂表面形成桥式或双齿硝酸盐迅速反应生成N₂和H₂O，从而使其反应过程主要遵循L-H机理。其表面丰富的化学吸附氧O_α能加速NO氧化成NO₂的形成，从而促进快速选择性催化还原。这些因素使空气氛围下焙烧的V-Mo-P/TiO₂催化剂在低温段的NO脱除率优于氮气和氢气氛围下焙烧的催化剂。

关键词

焙烧气氛 / V-Mo-P/TiO₂催化剂 / 选择性催化还原 / 脱硝

Abstract

收起

Introduction

Selective catalytic reduction (SCR) technology is widely used due to the advantages of high denitrification efficiency and low operating cost. The existing commercial SCR catalysts are mainly vanadium-based catalysts with V₂O₅ as an active component, metal oxides WO₃ and MoO₃ as additives, and anatase TiO₂ as a carrier. They have a good denitrification activity at 320-420 ℃, but have a poor activity at a low temperature. The denitrification activity of vanadium-based catalysts is mainly related to their redox capacity, acidic sites, and chemisorbed oxygen. In order to improve their denitrification activity, in this work, V-Mo-P/TiO₂ catalysts were prepared by an impregnation-roasting method. The effect of roasting atmospheres (i.e., air, hydrogen, and nitrogen) on the active components and denitrification performance of vanadium-molybdenum-titanium catalysts (V-Mo-P/TiO₂) was investigated.

Methods

A certain amount of oxalic acid was added into deionized water and dissolved under stirring., Ammonium metavanadate was then added into the solution, heated at 100 ℃ and stirred until the solution became dark blue. Afterwards, ammonium molybdate and diammonium hydrogen phosphate were added into the solution. TiO₂ was added and impregnated into the solution under stirring for 2 h, and then dried in an oven at 108 ℃ for 12 h to obtain a precursor of V-Mo-P/TiO₂ catalysts. The precursor was ground, pressed, and sieved to 40-60 mesh and placed in a fixed-bed reactor, and then roasted in different gases (i.e., air, nitrogen, and hydrogen) at 450 ℃ for 4 h to obtain different catalyst samples, which were named Air-450 ℃, N₂-450 ℃, and H₂-450 ℃, respectively.

The structure of the catalysts was analyzed by a model PANalytical X-Pert PRO MPD X-ray diffractometer (XRD, PANALYTEC Co., the Netherlands). The pore structure of the catalysts was determined by a model NOVA2200e specific surface area analyzer (Kantar Instruments Co., USA). The surface elemental valence of the catalysts was characterized by a model ESCALAB250Xi Instrument (Thermo Co., USA). The elemental valence states on the catalyst surface were determined by an X-ray photoelectron spectroscope (XPS). The redox capacity and surface acidity of the catalysts were characterized with H₂-TPR and NH₃-TPD, respectively, and the NO adsorption on the catalyst surface was determined with NO-TPDe. Pyridine adsorption test (Py-FT IR) was performed using a model PE Spectrum II infrared spectrometer (PerkinElmer Co., USA) to characterize the types and strengths of the acidic sites on the catalyst surface.

The catalyst activity was tested in a fixed-bed reactor at a gas flow rate of 1400 mL/min, a NO concentration of 500 mg-Nm³, an O₂ concentration of 8%, and an NH₃∶NO volume ratio of 1∶1 at 80-300 ℃. The catalysts were used in a fixed-bed reactor with a gas flow rate of 1400 mL/min, a NO concentration of 500 mg-Nm³, an O₂ concentration of 8%, and an NH₃∶NO volume ratio of 1∶1. The denitrification tail gas was examined by a model OPTIMA7 flue gas analyzer (MRU Co., Germany) to calculate the denitrification efficiency of the catalyst.

Results and discussion

At 100-250 ℃, the NO conversion of Air, N₂, and H₂ catalysts increases with the increase of temperature. Clearly, the denitrification performance of the catalysts obtained by roasting in three atmospheres is different, and the denitrification activity in different gases follows an order of Air > N₂ > H₂, in which the catalysts roasted in air have the optimum low-temperature catalytic activity.

The ratios of V⁴⁺/(V⁴⁺+V⁵⁺) in the catalysts roasted in air, nitrogen, and hydrogen are 0.440, 0.482, and 0.538, respectively, indicating that more V⁴⁺ is produced in a reducing atmosphere. Roasting in air can oxidize V⁴⁺ to V⁵⁺ to a certain extent, thus increasing the percentage of V⁵⁺ on the catalyst surface and the amount of chemisorbed oxygen O_α. From the results of H₂-TPR reduction, the corresponding integral area sizes are Air-450 ℃> N₂-450 ℃> H₂-450 ℃, indicating that polymerized vanadium is more easily formed in air. From the results of the NH₃-TPD desorption, the NH₃ desorption of the Air-450 ℃ catalyst is more than that of other two catalysts, and the number of acidic sites is in the following order of Air-450 ℃> N₂-450 ℃> H₂-450 ℃. The results of Py-FT IR further show that the acidic sites on the surfaces of the three catalysts are mainly of B-acid and L-acid. Roasting in air can increase the number of B- and L-acidic sites of the catalysts simultaneously, in which the B-acidic sites increased integrated areas of the catalysts roasted in air, nitrogen, and hydrogen are 1695, 1254 and 481, respectively, which are also basically consistent with the results of the NH₃-TPD characterization. The results of NO-TPD desorption indicate that the catalyst surface at Air-450 ℃ is more prone to forming highly active bridged or double-toothed nitrates. The V—O bond and B acidic sites in polymerized vanadium make it easier for the catalyst to adsorb and activate NH₃ species, which then reacts rapidly with the bridged or double-dentate nitrates to generate N₂ and H₂O. The reaction process mainly follows the L-H mechanism. The abundant O_α on its surface accelerates the formation of NO oxidized to NO₂, promoting a rapid SCR reaction. The V-Mo-P/TiO₂ catalysts roasted in air are superior to those roasted in nitrogen and hydrogen in terms of NO removal in the low-temperature section.

Conclusions

V-Mo-P/TiO₂ catalysts for low-temperature denitrification were prepared by an impregnation method, and the denitrification activities of V-Mo-P/TiO₂ catalysts roasted in air, nitrogen, and hydrogen atmospheres were investigated. The order of their catalytic activities was as follows: air > nitrogen > hydrogen. The results of H₂-TPR and XPS revealed that the catalysts roasted in air had a larger proportion of exposed V⁵⁺ on their surfaces, and contained abundant chemisorbed oxygen O_α, which further accelerated the oxidation of NO to NO₂, and participated in the "fast SCR" reaction of denitrification. Moreover, the catalysts roasted in air at 450 ℃ were characterized by NH₃-TPD, Py-FT IR and NO-TPD, and the results indicated that the catalysts possessed more abundant B acid sites, and the B acid and polymerized vanadium were more prone to adsorption of activated NH₃ species, which further reacted with the bridged and double-toothed nitrate formed on the surface of the catalysts to generate N₂ and H₂O, thus promoting the SCR denitrification reaction by L-H mechanism.

Key words

calcination atmosphere / V-Mo-P/TiO₂ catalysts / selective catalytic reduction / denitrification

引用本文

吴雪莲, 程会, 余通, 张昭军, 王琪, 魏凤玉, 王梦瑜. 焙烧气氛对V-Mo-P/TiO₂催化还原脱硝性能的影响. 硅酸盐学报, 2025 , 53 (7) : 1952 -1961 . DOI: 10.14062/j.issn.0454-5648.20240657

Xuelian WU, Hui CHENG, Tong YU, Zhaojun ZHANG, Qi WANG, Fengyu WEI, Mengyu WANG. Effect of Calcination Atmosphere on Catalytic Reduction Denitrification Performance of V-Mo-P/TiO₂[J]. Journal of the Chinese Ceramic Society, 2025 , 53 (7) : 1952 -1961 . DOI: 10.14062/j.issn.0454-5648.20240657

基金

收起

中央高校基本科研业务费专项资金资助(PA2024GDSK0101)

参考文献

收起

文献

收起

参考文献引证文献

排序方式：

2025年第53卷第7期

PDF下载

引用本文

BibTeX

文章信息

doi: 10.14062/j.issn.0454-5648.20240657

接收时间：2024-10-16
首发时间：2026-10-21
出版时间：2025-07-20

补充材料

相关文章

文章信息

作者

出版历史

收稿日期：2024-10-16
修回日期：2024-11-19

基金

中央高校基本科研业务费专项资金资助(PA2024GDSK0101)

作者信息

^1．合肥工业大学化学与化工学院，高值催化转化与反应工程安徽省重点实验室，合肥 230009

^2．合肥中亚环保科技有限公司，合肥 230051

通讯作者:

王琪（1978—），男，博士，副教授。

参考文献

分享链接

https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20240657

分享至

全文二维码

扫描看全文

引用本文

BibTeX

本文的引用情况

2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

关闭全屏

BibTeX
EndNote
RefWorks
TxT