ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Fei Wang,Zhibo Xie,Jinsheng Liang,Baizeng Fang,Yu’ang Piao,Ming Hao,Zishuo Wang
Low temperature NH3 selective catalytic reduction (NH3-SCR) technology is an efficient and economical strategy for cutting NOx emissions from power-generating equipment. In this study, a novel and highly efficient NH3-SCR catalyst, tourmaline-modified FeMnTiOx is presented, which was synthesized by a simple one-step sol–gel method. We found that the amount of tourmaline has an important impact on the catalytic performance of the modified FeMnTiOx-based catalysts, and the NOx conversion exceeded 80% from 160 to 380 °C with the addition of 5 wt % tourmaline. Compared with the pure FeMnTiOx, the catalytic efficiency at a temperature below 100 °C was increased by nearly 18.9%, and the operation temperature window was broadened significantly. The enhanced catalytic performance of the FeMnTiOx catalyst was mainly attributed to the small spherical nanoparticles structure around the tourmaline powders, resulting in the increased content of Mn3+, Mn4+, and chemical oxygen on the catalytic surface. These as-developed tourmaline-modified FeMnTiOx materials have been demonstrated to be promising as a new type highly efficient low temperature NH3-SCR catalyst.
研究领域:
环境科学
·
催化材料
·
能源工程
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 24
·30243-30253
·
IF 3.056
Xu Wenqing,Gao Lei,Yang Yang,Zhu Tingyu,Qi Guisheng
The deposition of NH 4 HSO 4 on catalysts is one of the key issues for selective catalytic reduction of NO x . In this study, NH 4 HSO 4 was preloaded on catalysts, and the effects of MoO 3 and CeO 2 doping on the decomposition and reactivity of NH 4 HSO 4 on V 2 O 5 /TiO 2 catalysts are studied. The results show that the introduction of MoO 3 and CeO 2 significantly promoted NO x conversion on the V 2 O 5 /TiO 2 catalysts. Doping with MoO 3 could effectively enhance the S and H 2 O resistance of the catalysts. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicate that it is the strong chemical interactions between NH 4 HSO 4 and the catalysts that are adverse to the decomposition of NH 4 HSO 4 . However, doping with MoO 3 apparently inhibits these interactions, which significantly decrease the decomposition temperature of NH 4 HSO 4 . In situ FTIR experiments show that the NH 4 + in preloaded NH 4 HSO 4 could react with gaseous NO on catalysts, and doping with MoO 3 could facilitate the reaction rate.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Shaomian Liu,Wenjuan Xue,Yongjun Ji,Wenqing Xu,Wenxing Chen,Lihua Jia,Tingyu Zhu,Ziyi Zhong,Guangwen Xu,Donghai Mei,Fabing Su
Simultaneously improving both NO x conversion and N 2 selectivity in the selective catalytic reduction of NO by CO (CO-SCR) under O 2 -containing conditions is highly challenging because of the competitive reactions of NO x and CO with O 2 . Here, we demonstrate that the interfacial oxygen vacancies (IOVs) generated at the Co 3 O 4 -CeO 2 heterointerfaces by ball-milling-induced strain can remarkably boost both NO x conversion and N 2 selectivity in the temperature range of 100–400 °C. The Co 3 O 4 -CeO 2 -IOV catalyst achieved approximately 100% NO x conversion and 100% N 2 selectivity (200–350 °C, 1–5 vol% O 2 , and 20,000 h −1 ); even under 10 vol% O 2 , it still showed good catalytic performance. The spectroscopy analysis and theoretical calculations reveal that compared with O 2 activation, IOVs are more favorable for the rate-limiting step of NO adsorption and dissociation. This work provides an effective strategy to create IOVs within metal oxide composite catalysts using ball-milling-induced interfacial strain for improving CO-SCR performance.
研究领域:
材料科学
·
环境催化
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2025
·
IF 5.3
Fang Wang,Xueyan Wu,Yuxuan Han,Yan Lv,Jixi Guo,Xiaoman Li,Yaping Zhang
In cement kiln flue gas emissions, high concentrations of alkali and alkaline earth metals cause the deactivation of the NbCe/Ti catalysts, significantly reducing their operational lifespan under industrial conditions. Here, the NbCe-loaded titanium nanotubes (NbCe/TiNTs) catalyst has been synthesized via hydrothermal and impregnation methods. The NbCe/TiNTs catalyst exhibits superior resistance to potassium (K) and calcium (Ca) poisoning. Notably, NbCe/TiNTs catalyst maintains high NOx conversion across a wide temperature range (192–350 °C). The 5Ca-NbCe/TiNTs and 3K-NbCe/TiNTs catalysts achieve a 90% NOx conversion at 235 and 242 °C, respectively, demonstrating remarkable resistance to K and Ca poisoning. The results indicate that TiNTs supports enhance both the specific surface area and surface acid sites of the catalyst, synergistically improving its resistance to K and Ca poisoning. Furthermore, an in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study elucidates selective catalytic reduction with the NH3 (NH3-SCR) reaction mechanism, revealing dual contributions from both the Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms on the catalyst. This work provides a research direction for enhancing the alkali poisoning resistance of NOx removal catalysts.
研究领域:
环境催化
·
材料科学
·
化学工程
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
Engineering
·
2025
·
IF 11.6
Ying Zhu,Jingjing Liu,Guangzhi He,Shaohua Xie,Wenpo Shan,Zhihua Lian,Fudong Liu,Hong He
Catalytic activity and hydrothermal stability are both crucial for the application of the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR catalyst) in diesel vehicles. In this study, a tin (Sn)-modified Ce–Nb mixed-oxide catalyst was synthesized as an NH 3 -SCR catalyst for NO x emission control. After the introduction of Sn, both the NH 3 -SCR activity and the hydrothermal stability of the catalyst were remarkably promoted. Even after hydrothermal aging at 1000 °C, the developed Ce 1 Sn 2 Nb 1 O x catalyst achieved more than 90% NO x conversion at 325–500 °C. Various methods, including N 2 -physisorption, X-ray diffraction, in-situ high-temperature X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption fine-structure spectroscopy, temperature-programmed reduction of hydrogen, temperature-programmed desorption of ammonia, and density functional theory calculations were used to investigate the promotional effects induced by the Sn species. The characterization results showed that the addition of Sn not only promoted the formation of the Ce–Nb active phase but also improved its thermal stability, contributing to the excellent NH 3 -SCR performance and hydrothermal stability. This study provides an excellent sintering-resistance catalyst for the application of diesel engine NO x emission control.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 98
·期 2
·506-515
·
IF 3.709
Cao Shuang,Zhang Haixiang,Wang Xueman,Peng Miquan,Huang Renhua,Hong Wei,Fu Hailu,Chen Xiongbo,Lin Zejian
In SCR denitrification technology, the conventional coprecipitation method has the disadvantages of high temperature and difficulty in controlling the precipitation rate. Various Ce x CuTiO 2 catalysts were synthesized using ice-melting (Ce x CuTi-Ice) and conventional coprecipitation (Ce x CuTi-Con) methods for the selective catalytic reduction (SCR) of NO with NH 3 . Ce 0.4 CuTi-Ice catalyst exhibited excellent catalytic activity among the Ce x CuTiO 2 catalysts, and 80% NO x conversion was achieved within a temperature range of 250–375 °C, exceeding that of Ce 0.4 CuTi-Con catalyst by 20%; in addition, N 2 selectivity was nearly 100%. To elucidate the release characteristics of the precursor solution during ice-melting synthesis, the changes of Cu and Ce concentrations in the solution were investigated by ICP-OES. The precursor solution was released at a slow rate via the ice-melting method, resulting in a large surface area, small crystallite sizes, and effective uniform nanoparticles with abundant active species and increased surface acidity. The promoted mechanism could be attributed to the enhanced oxidation of NO to NO 2 at low temperatures and the rapid reaction between NO species and coordinated NH 3 at high temperatures. © 2022 Society of Chemical Industry (SCI).
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2023
·Vol. 13
·期 10
·3147-3157
·
IF 5
Hange Wang,Wen Chen,Wei Jin,Yueli Liu
SCR technology is considered to be the most effective method for denitrification. However, the low NOx conversion rate of the current catalysts at low temperatures limits their further application. Herein, Sn-doped modified CoAl-LDH carriers are synthesized by a hydrothermal method, and the typical hexagonal sheet structure of the MnOx(0.25)/CoSn3Al-LDO catalyst achieves 100% NO conversion at a wide range of 120–330 °C with a GHSV of 30 000 h−1, and the 100% NO conversion may be maintained at 200 °C for 30 h. After the introduction of 150 ppm SO2 at 200 °C, the NO conversion of the MnOx(0.25)/CoSn3Al-LDO catalyst is maintained at 73.4%, which is greatly improved compared with those of CoAl-LDO and MnOx(0.25)/CoAL-LDO catalysts (64.8% and 38.6%, respectively). The active components such as MnOx and Co3O4 are highly dispersed in the MnOx(0.25)/CoSn3Al-LDO catalyst. Sn doping increases the ratios of Mn4+/Mn3+ and Co3+/Co2+ as well as the adsorbed oxygen amount on the catalyst surface, and improves the redox capacity of the catalyst and increases the number of acid sites, resulting in the excellent low-temperature NH3-SCR performance of MnOx(0.25)/CoSn3Al-LDO.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Kaiqi Wang,Bo Lin,Wende Xiao
A coprecipitation approach was used to prepare vanadium–molybdenum composite oxide catalysts, which were then calcined at 300, 400, 500, 600, and 700 °C. The vanadium–molybdenum catalyst, under calcination at 500 °C, possesses abundant surface defects and acid species. As a result, it showed an outstanding active window, achieving over 90% NOx conversion efficiency within the temperature range of 220–340 °C. Compared with other catalysts, the vanadium–molybdenum catalyst with the calcination at 500 °C resulted in the formation of polymeric vanadate with the most active oxygen, which was conducive to the high catalytic efficiency for the NH3-SCR reaction. Based on our in-depth understanding gained from in situ DRIFTS experiments, we proposed that the NH3-SCR reaction occurred on the vanadium–molybdenum catalyst via an Eley–Rideal pathway. This mechanism involves the initial adsorption of ammonia on the catalytic surface, followed by its interaction with weakly adsorbed or gaseous NO to form an activated complex. Furthermore, the presence of molecular oxygen (O2) serves to augment the adsorption and activation of nitric oxide over the catalytic surface. The augmentation arises from the generation of adsorbed NO2 species or nitrates, which possess pronounced oxidizing capabilities. Notably, the significant impact of NH3 and NO in the denitration reaction was elucidated, providing valuable insights that can guide the adjustment and optimization of practical operational conditions. This understanding is crucial for enhancing the efficiency and effectiveness of the denitration process, thereby contributing to improved environmental qualities.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 15
·4863
·
IF 4.927
Shun Li,Zuquan Zheng,Zhicheng Zhao,Youling Wang,Yao Yao,Yong Liu,Jianming Zhang,Zuotai Zhang
CeO2nanoparticle-loaded MnO2nanoflowers, prepared by a hydrothermal method followed by an adsorption-calcination technique, were utilized for selective catalytic reduction (SCR) of NOxwith NH3at low temperatures. The effects of Ce/Mn ratio and thermal calcination temperature on the NH3–SCR activity of the CeO2-MnO2nanocomposites were studied comprehensively. The as-prepared CeO2-MnO2catalysts show high NOxreduction efficiency in the temperature range of 150–300 °C, with a complete NOxconversion at 200 °C for the optimal sample. The excellent NH3–SCR performance could be ascribed to high surface area, intimate contact, and strong synergistic interaction between CeO2nanoparticles and MnO2nanoflowers of the well-designed composite catalyst. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) characterizations evidence that the SCR reaction on the surface of the CeO2-MnO2nanocomposites mainly follows the Langmuir–Hinshelwood (L-H) mechanism. Our work provides useful guidance for the development of composite oxide-based low temperature NH3–SCR catalysts.Keywords:Mn-Ce mixed oxide;ion-adsorption;selective catalytic reduction;NOxconversion
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2019
·Vol. 128
·期 2
·681-693
·
IF 1.428
Xie Chong,Yang Shenghui,Shi Jian-Wen,Niu Chunming
A novel MnO x –TiO 2 catalyst with hollow silkworm structure was synthesized successfully via an ethanol-thermal strategy by using activated carbon fiber felt as template for the first time. The silkworm-like MnO x –TiO 2 catalyst (MnTi) exhibited higher NO x conversion in the whole experimental temperature region (90–330 °C) under a high space velocity of 36,000 h −1 in comparison with the common MnO x –TiO 2 catalyst without hollow silkworm structure (MnTi-B). The excellent catalytic performance of MnTi can be attributed to its high specific surface area, large content of active surface oxygen species (O S ), and more surface acid sites. In addition, the MnTi catalyst also exhibited excellent resistance to water or SO 2 poisoning.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2023
·
IF 3.7
Jiuhu Zhao,Huiying Li,Yungang Wang,Rongshu Zhu,Senlin Sun,Jingwen Zhang,Chaolin Li,Mei Hong
Mesoporous In/Hβ-X series catalysts were prepared by desilication method with tetrapropylammonium hydroxide (TPAOH) and indium incorporation for selective catalytic reduction of NO with methane (CH 4 -SCR). The post desilication treatment conditions for preparing In/Hβ-X were optimized. Etching time is the most important desilication parameter influencing the resulting CH 4 -SCR performance of the catalyst. The In/Hβ-3 sample which was etched for 3 h presents the highest NO x conversion, 22% higher than In/H-Beta counterparts using commercial microporous beta. Obvious analysis reveals that besides generating mesopores, controlled desilication can modulate the proportion of InO + active sites and surface oxygen species, allowing more active sites to be exposed.
研究领域:
催化
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Chengzhi Wang,Fengyu Gao,Songjin Ko,Hengheng Liu,Honghong Yi,Xiaolong Tang
The presence of SO 2 in industrial flue gases will cause permanent deactivation of the catalyst active centre. Therefore, an effective method to improve the SO 2 resistance of manganese-based catalysts at low temperatures is urgently needed. In this work, a hierarchical porous nanowire structure catalyst was designed by the in situ self-assembly method to inhibit SO 2 adsorption. This hierarchical porous nanowire aerogel catalyst with great BET surface area and surface acidity exhibited NOx conversion above 90% at 100–400 °C. Notably, the NOx conversion of the MnCe-N catalyst was almost not inhibited by SO 2 (250 ppm) compared to the 33% decrease of the MnCe-P catalyst. On the MnCe-P catalyst, SO 2 has strong competitive adsorption with NH 3 and NO, and the stronger adsorption capacity of SO 2 inhibits the adsorption activation of the reaction gas and hinders the reaction proceeding through the L-H mechanism. Meanwhile, a large quantity of sulfate is formed on the catalyst surface, which prevents the active centre to participate in the redox reaction. The structure of nanowires enhances the number of acid sites, facilitates the adsorption and activation of NH 3 , and effectively inhibits the adsorption of SO 2 on the MnCe-N catalyst. Fewer sulfate species are generated and difficult to deposit and aggregate on the catalyst surface, as a result, the active centre is less affected by sulfate species. The stable adsorption of NH 3 -related species ensures reliable reaction on MnCe-N through the E-R mechanism. This work emphasizes the importance of hierarchically porous structures in improving the NH 3 -SCR performance and SO 2 resistance of monolithic catalysts, and provides new insights into the design of highly efficient and stable catalytic materials.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）