APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Jingjing Liu,Mengyuan Zhang,Diru Liu,Yunbo Yu,Guangyan Xu,Hong He
Ammonia selective catalytic reduction (NH 3 -SCR) of nitrogen oxides (NO x ) is a widely adopted method for controlling NO x emissions. However, achieving superior low-temperature activity while maintaining high N 2 selectivity over a broad temperature range remains a major challenge. In this study, a novel mesoporous manganese–titanium–aluminum (Mn-Ti-MA-S) composite oxide catalyst was synthesized by a modified evaporation-induced self-assembly method. The incorporation of Mn and Ti into mesoporous alumina (MA) framework significantly optimized the redox-acidic properties of the Mn-Ti-MA catalyst, with Mn in a highly dispersed state with fully exposed microcrystalline structures. Subsequent sulfur treatment further transformed the Lewis acid sites into Brønsted acid sites, shifting the reaction pathway from a Lewis acid site-dominated to Brønsted acid site-dominated mechanism. This strategy successfully overcame the conventional trade-off between low-temperature activity and high-temperature N 2 selectivity in NH 3 -SCR catalysts. Consequently, the optimized Mn-Ti-MA-S catalyst exhibited excellent catalytic performance, achieving both NO x conversion and N 2 selectivity above 90 % over a wide temperature range (104–400 °C). This work highlights a synergistic strategy that integrates redox and acid sites engineering with reaction pathway regulation, enabling the development of highly efficient NH 3 -SCR catalysts.
研究领域:
环境催化
·
材料科学
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化学工程
·
大气污染控制
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2017
·Vol. 19
·期 7
·5333-5342
·
IF 4.123
Shu-xian Wang,Rui-tang Guo,Wei-guo Pan,Ming-yuan Li,Peng Sun,Shu-ming Liu,Shuai-wei Liu,Xiao Sun,Jian Liu
It was well recognized that Pb had a poisoning effect on a SCR catalyst. In this study, the deactivation mechanism of Pb on the Ce/TiO2 catalyst was investigated based on the characterization results of TPD and in situ DRIFT studies. It was found that the addition of Pb on the Ce/TiO2 catalyst not only inhibited the adsorption and activation of NH3 species, but also led to the decrease of the activity of adsorbed NH3 species in the SCR reaction. The adsorption of NOx species and the oxidation of NO by O2 over the Ce/TiO2 catalyst were also suppressed by the addition of Pb, while the reactivity of adsorbed NO2 species did not decrease. Moreover, the results revealed that the NH3-SCR reaction over the Ce/TiO2 catalyst followed both the E–R and L–H mechanisms, while the NH3-SCR reaction over Ce/TiO2-Pb was mainly controlled by the L–H mechanism. The contributions of the L–H mechanism to the SCR reactions over Ce/TiO2 and Ce/TiO2-Pb decreased with increasing reaction temperature. The deactivation of Ce/TiO2-Pb was mainly attributed to the suppressed NH3 adsorption and activation, accompanied by the inhibited NO oxidation and the decrease of Brønsted acid sites.
研究领域:
环境催化
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大气污染控制
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材料化学
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表面科学
·
物理化学
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 86
·82707-82715
·
IF 3.289
Wei Li,Rui-tang Guo,Shu-xian Wang,Wei-guo Pan,Qi-lin Chen,Ming-yuan Li,Peng Sun,Shu-ming Liu
A series of Mn/CeSiOx catalysts were prepared by the wet impregnation method and used for selective catalytic reduction of NO with NH3. As can be seen from the experimental results, the Mn/CeSiOx catalyst with a Ce/Si molar ratio of 2/1 showed excellent low-temperature SCR activity, high N2 selectivity and excellent SO2 and H2O tolerance. The relationship between the CeSiOx support and the SCR performance of Mn/CeSiOx (2 : 1) catalyst was investigated based on the characterization results of N2 adsorption, XRD, XPS, H2-TPR, NH3-TPD and in situ DRIFT. The strong interaction between Ce and Si resulted in the good dispersion of Mn species on the support; correspondingly, the redox ability and NH3 adsorption capacity were greatly enhanced. The results of in situ DRIFT study revealed that the NH3-SCR reactions over Mn/CeO2 and Mn/CeSiOx (2 : 1) mainly obeyed both the E–R mechanism and the L–H mechanism. Furthermore, the formation of more Mn4+ and chemisorbed oxygen greatly facilitates the oxidation of NO to NO2, as a result, promoting the low-temperature SCR performance of Mn/CeSiOx (2 : 1).
研究领域:
催化
·
环境科学
·
化工
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DOI
高影响因子
CHEMICAL PAPERS
·
2017
·Vol. 72
·期 1
·51-56
·
IF 1.258
Wei Mengyi,Qian Chao,Chen Xinzhi
Based on the recycling of NO
x
, the Cu(I)- and HNO 3 -catalyzed oxidation of 2-chloro-4-(methylsulfonyl)toluene to 2-chloro-4-(methylsulfonyl)benzoic acid has been developed with an excellent yield of 84.2% and a purity of 99.7%. The optimized reaction conditions (160 °C, oxygen pressure 1.5 MPa, HNO 3 concentration 25 wt%, HNO 3 : substrate 0.5:1) use 1.0 mol% CuI as catalyst. The dosage of HNO 3 in the new process is only 25% of the stoichiometric amount and 12.5% of the amount of the traditional process. The NO
x
emission is 5% amount of the traditional process. The oxidation of several additional toluene derivatives with comparable yields demonstrates the generality to these reaction conditions.
研究领域:
化学
·
环境科学
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DOI
高影响因子
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
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DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Jiangxiao Qiao,Jinxin Gan,Fei Gao,Xiangsen Xu,Jiesong Tan,Yiqing Zeng,Feng Zhang,Feng Han,Zhaoxiang Zhong,Weihong Xing
Synergistic removal of nitrogen oxides (NOx) and particulate matter (PM) can be achieved using multifunctional catalytic membranes. In this work, CePO4 nanorods were loaded on the pore surfaces of SiC membranes to construct the CePO4/SiC-X catalytic membranes. The stacked nanorod structure of the CePO4 catalyst layer facilitates the diffusion of gases to the catalyst surface during reactions. Owing to the high specific surface area, rich surface acidity, and strong redox capacity, the CePO4/SiC-400 catalytic membrane exhibits the best ammonia-selective catalytic reduction (NH3–SCR) denitration activity, achieving >90% NO conversion at a temperature of 250–380 °C and negligible N2O byproduct. In addition, the CePO4/SiC-400 catalytic membrane demonstrates excellent H2O and SO2 resistance. The performance of dust filtration and simultaneous dust filtration and denitration at 250–350 °C proposed that the dust rejection efficiency reached more than 99% at various conditions, and the dust filtration process did not affect the NH3–SCR performance of the CePO4/SiC-400 catalytic membrane. From the above results, the CePO4/SiC-400 catalytic membrane presents a broad application prospect in the simultaneous dust removal and denitration of high-temperature flue gas.
研究领域:
环境科学
·
催化材料
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PLoS One
·
2018
·Vol. 13
·期 4
·e0192324
·
IF 2.766
Hai-qian Zhao,Zhong-hua Wang,Xing-cun Gao,Cheng-hao Liu,Han-bing Qi
H 2 O 2 was adopted to oxidize NO in simulated flue gas at 100–500°C. The effects of the H 2 O 2 evaporation conditions, gas temperature, initial NO concentration, H 2 O 2 concentration, and H 2 O 2 :NO molar ratio on the oxidation efficiency of NO were investigated. The reason for the narrow NO oxidation temperature range near 500°C was determined. The NO oxidation products were analyzed. The removal of NO x using NaOH solution at a moderate oxidation ratio was studied. It was proven that rapid evaporation of the H 2 O 2 solution was critical to increase the NO oxidation efficiency and broaden the oxidation temperature range. the NO oxidation efficiency was above 50% at 300–500°C by contacting the outlet of the syringe needle and the stainless-steel gas pipe together to spread H 2 O 2 solution into a thin film on the surface of the stainless-steel gas pipe, which greatly accelerated the evaporation of H 2 O 2 . The NO oxidation efficiency and the NO oxidation rate increased with increasing initial NO concentration. This method was more effective for the oxidation of NO at high concentrations. H 2 O 2 solution with a concentration higher than 15% was more efficient in oxidizing NO. High temperatures decreased the influence of the H 2 O 2 concentration on the NO oxidation efficiency. The oxidation efficiency of NO increased with an increase in the H 2 O 2 :NO molar ratio, but the ratio of H 2 O 2 to oxidized NO decreased. Over 80% of the NO oxidation product was NO 2 , which indicated that the oxidation ratio of NO did not need to be very high. An 86.7% NO removal efficiency was obtained at an oxidation ratio of only 53.8% when combined with alkali absorption.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2021
·
IF 6.141
Heyang Si,Mengyuan Zhou,Yongle Fang,Jianhui He,Lu Yang,Fazhou Wang
The application of titanium dioxide (TiO 2 ) photocatalyst in concrete is considered a promising method to effective remove nitrogen oxide (NOx) pollutants. However, the influences of application ways on photocatalytic efficiency and catalyst durability should be concerned in detail for its large-scale application. This paper compared the photocatalytic NOx degradation efficiency and durability of conventional TiO 2 powder dispersed in cement mortar (TPC), TiO 2 supported aggregates mounted on cement mortar surface (TAS) and TiO 2 supported aggregates dispersed in cement mortar (TAD), with considering different environmental factors effects such as gas flow rate, NO initial concentration and relative humidity. The photocatalytic efficiency results show that the NOx removal efficiency of TAS is about 1.5 and 1.1 times higher than that of TPC and TAD, respectively, corresponding to the utilization efficiency of TiO 2 photocatalysts in TAS is ca. 10 and 16 times higher than in TPC and TAD, respectively. The surface abrasion test suggests that TAS has relatively low photocatalytic efficiency compared with TAD after polishing the sample surface by more than 2 mm, which depends on the mounted thickness of TiO 2 supported aggregates. The findings in this work can provide the basis for the application ways of TiO 2 supported aggregates in concrete by considering its photocatalytic efficiency, economic efficiency and catalytic durability.
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产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2025
·
IF 7.4
Huimin Chen,Xin Li,Wenjiang Li,Aoao Lu,Chenguang Li,Qiang Li,Dabin Liu,Hongfei Ma,Binbin Wang
The safe long-term storage of nitrocellulose (NC) has become increasingly challenging under extreme environmental conditions due to accelerated NO x release, which promotes self-catalytic decomposition of NC. In this study, Tröger’s base (TB) was integrated into porous organic polymers (POPs) to achieve dual functionality: efficient physical adsorption and stable in-situ chemical fixation of NO x within confined pore spaces. Solid-state CP/MAS 13 C NMR spectroscopy and quantum chemical calculations were employed to confirm that NO x immobilization occurs preferentially at the ortho positions of tertiary amine moieties on aromatic rings. Among the synthesized materials, the polymer resulting from the Trögerization of the Tetrakis (4-aminophenyl) methane (TAPM-TB) was identified as the optimal adsorbent, characterized by accessible ortho-active sites, a microporous structure, and an exceptional NO x uptake capacity of 3.31 mmol/g under standard conditions. Furthermore, TAPM-TB was demonstrated to extend the stability time of NC by 3.23 times in methyl violet tests. These findings highlight a novel strategy for designing materials capable of simultaneous physical adsorption and stable chemical immobilization of NO x or other gases.
研究领域:
材料科学
·
环境化学
·
高分子化学
·
物理化学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Jiashan Chen,Ge Pu,Jian Li
xMo/TiO2 catalysts (x = 1, 2, 3, and 4%) were prepared using the coprecipitation method in the present study. The coprecipitation method was used in the thermal catalytic decomposition of H2O2 steam to treat NOx at a low temperature range (80–160 °C). Several characterization techniques have been employed, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller measurements, transmission electron microscopy (TEM), scanning electron microscopy and energy-dispersive X-ray spectrometry (SEM–EDXS), and Fourier transform infrared spectroscopy. The activity tests showed that the incorporation of molybdenum into TiO2 led to a significant increase in the catalytic oxidation of NO, and under the condition of H2O2/NO = 6:1 (molar ratio), the NOx removal rate of 2% Mo/TiO2 is the highest, reaching 92.56%. XRD, TEM, and SEM–EDXS analyses showed that Mo was well dispersed on the surface of an anatase-phase TiO2. XPS analysis indicated that Mo mixed with slag mainly existed in the form of Mo6+. Moreover, in comparison with the mostly reported SCO catalysts, used for the elimination of NO, the prepared Mo/TiO2 catalyst showed excellent stability and sulfur resistance.
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产品关联
DOI
PubMed
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
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·
IF 0
You Mengyun,Wu Shufeng,Feng Xiaotong,Zhao Yong,Wang Yubin,Zhang Zhang
The enhancement effect of Ce modification on V 2 O 5 -WO 3 /TiO 2 catalysts at low temperatures was investigated for the selective catalytic reduction (SCR) of NO x with NH 3 (NH 3 -SCR). By adding 9% CeO 2 to 0.5%V 2 O 5 -3%WO 3 /TiO 2 catalyst, the low-temperature denitrification performance of Ce 9 V 0.5 W 3 Ti catalyst after Ce modification was significantly improved, achieving a NO conversion above 90% within a broad temperature range of 200–350℃, with catalytic activity comparable to that of 3% V 2 O 5 -3% WO 3 /TiO 2 . The catalysts were characterized by XPS, H 2 -TPR, NH 3 , and NO-TPD. The results indicated that the Ce additive could enhance the adsorption of NO x on Ce 9 V 0.5 W 3 Ti catalyst due to the synergetic interaction among the Ce and V, W species. The interaction between V and Ce also promoted the formation of V 5+ and Ce 3+ on the surface of the catalyst, which was conducive to enhancing the adsorption and oxidation capacity of the catalyst for NO. Additionally, the introduction of Ce led to a substantial deposition of nitrate species on the surface of the catalyst, especially the increase of nitrite species, which was beneficial to the NH 3 -SCR reaction process, resulting in a significant enhancement of the catalyst’s low-temperature catalytic activity.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
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