Advances in Materials Science and Engineering
·
2019
·
IF 1.399
Zhuo Yao,Dianli Qu,Yuxiang Guo,Yujing Yang,Hong Huang
Novel catalysts with high activity for the selective catalytic reduction of NO with NH3 (NH3-SCR) at low temperatures are highly demanded. In this study, mixed-node metal-organic frameworks (MOFs), e.g. Mn@CuBTC with controlled Mn composition in Cu3(BTC)2, were fabricated using postsynthetic exchange method and their structural characteristics and catalytic performances for NH3-SCR reaction were assessed. A series of analyses in terms of structure, surface morphology, texture, and chemical state determined that Mn ions were successfully incorporated into the Cu3(BTC)2 crystal lattice as well as adsorbed on the walls of nanopores in the framework. The pore sizes can be finely tuned in the presence of Mn ions in the cages, which significantly suppressed water adsorption. The NH3-SCR activity of Mn@CuBTC exhibited nearly 100% NOx conversion rate in the temperature range (230–260°C). The superior NH3-SCR performance is attributed to the proper pore sizes, reduced water content, and the synergistic effect between manganese and copper ions in the MOF structure, which enhanced NH3 bound to the active Lewis sites.
研究领域:
材料科学
·
催化化学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Weiyuan Yao,Yue Liu,Zhongbiao Wu
A series of CeO 2 @Ce-O-P “multi-core@shell” catalysts were synthesized in this paper for selective catalytic reduction (SCR) of NO with NH 3 . The experimental results had showed that CeO 2 @Ce-O-P-30:3 yielded best SO 2 tolerance of an over 70% deNO x efficiency at 250 °C in the presence of 100 ppm SO 2 for 20 h, which was much higher compared to pure Ce-O-P and CeO 2 samples. Further characterization results indicated that Ce-O-P coating layer could somewhat inhibit sulfur depositing on the catalysts during SCR reaction in the presence of SO 2 , thereby protecting the active sites from SO 2 poisoning. Especially, O 2 -TPD results illustrated that a great amount of active oxygen species were retained on used CeO 2 @Ce-O-P catalyst after a long term reaction. The synergetic effect of “multi-core@shell” structure could be attributed to such enhanced performances. The “core” CeO 2 devoted abundant active oxygen sites to fulfill the SCR reaction. And the “shell” Ce-O-P could not only provide acid sites, but also protect the active oxygen species by avoiding the over-adsorption of SO 2 on the catalyst. This work could provide a new way to increase the sulfur resistance for low temperature SCR catalysts.
研究领域:
催化化学
·
环境科学
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高影响因子
CATALYSIS TODAY
·
2020
·
IF 5.825
Ye Ma,Shichao Han,Qinming Wu,Longfeng Zhu,Huimin Luan,Xiangju Meng,Feng-Shou Xiao
The metal-exchanged zeolites as catalysts have been widely applied in many catalytic reactions , but their syntheses are environmentally unfriendly due to the multiple steps such as ion-exchange for the formation of a large amount of wastes. Herein, we for the first time report a method for one-pot fabrication of metal-zeolite catalysts (M-SSZ-13, M-Beta, M-ZSM-5, and M-EU-1; M = Cu, Co, Ni) from a combination of solvent-free and sodium-free routes by mixing, grinding, and heating the raw materials of aluminosilicate gel, organic templates, and metal-amine complexes. As a typical example, Cu-SSZ-13 zeolite is successfully synthesized from heating the mixture of aluminosilicate gel, organic template, and Cu-amine complex. Catalytic tests in selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) show that the synthesized Cu-SSZ-13 zeolite before and after hydrothermal aging at 750 °C for 16 h are completely comparable with the commercial Cu-SSZ-13 zeolite from the conventional hydrothermal synthesis. Very interestingly, the method in this work has obvious advantages such as high yield, reduced pollutants, and simple process, which should be potentially important for practical applications of the metal-zeolites in the future.
研究领域:
催化化学
·
环境科学
·
材料科学
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yuqing Pan,Na Li,Shiyuan Ran,Du Wen,Qinlan Luo,Ke Li,Qulan Zhou
Efforts have been devoted to exploring the effective composite catalysts for low-temperature selective catalytic reduction of NOx by CO (CO-SCR) using Fe-Cu bimetal oxide (Fe2Cu1) as the active component and rice husk ash (RHA), amorphous SiO2, and activated carbon (AC) as supports. The results showed that the beneficial role of RHA as a catalyst support for CO-SCR was primarily reliant on amorphous SiO2 in RHA and not on AC. Both Fe2Cu1/RHA and Fe2Cu1/amorphous SiO2 catalysts exhibited the best catalytic performance of CO-SCR, which had good stability, wide active temperature range, high conversion ratio, 100% N2 selectivity, and superior resistance to O2, SO2, and H2O (g). The CO and NOx conversion ratios of Fe2Cu1/amorphous SiO2 could reach up to approximately 100% from 100 to 500 °C. The excellent SCR performance was associated with the large specific surface area and good structural stability of amorphous SiO2, the uniform distribution of active sites, dual redox cycle of Fe2O3 and CuO species, and many surface-adsorbed oxygen species, which made amorphous SiO2-based catalysts highly competitive for application in the SCR process. This research provides the underlying insights for the improvement of industrial application to realize ″non-ammonia SCR″ technology with near-zero NOx/CO emissions synergistically at low temperatures.
研究领域:
环境科学
·
催化化学
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2026
·
IF 21.1
Jie Yang,Yu Luo,Zhichao Chen,Junjiang Zhu
The selective catalytic reduction of NO with NH 3 (NH 3 −SCR) reaction is governed by the interplay of surface acidity and redox activity, yet the mechanism of their cooperation remains elusive. Herein, Ce–O–W linkages were constructed on Ce/ZrO 2 to couple Ce 4+ /Ce 3+ redox cycle with tungsten-derived acidity. Operando DRIFTS and transient experiments revealed that gaseous NO reacts directly with NH 3 adsorbed on Lewis Ce 4+ sites, following an Eley–Rideal pathway. Brønsted acid sites from Ce–O–W acted as NH 4 + reservoirs, dynamically replenishing Lewis-bound NH 3 and sustaining continuous reactivity. Operando UV–vis spectroscopy confirmed that NO + NH 3 exposure reduced Ce 4+ to Ce 3+ , while O 2 re-oxidized Ce 3+ to Ce 4+ , establishing the redox cycle. Density functional theory calculations supported that NH 3 dehydrogenation on Ce sites and subsequent coupling with gaseous NO were energetically favorable, while O 2 -assisted Ce 3+ re-oxidation required the highest energy barrier. These results highlight the cooperative function of Ce–O–W acid–redox site in promoting SCR activity through dynamic L–NH 3 /B–NH 4 + interplay and sustained Ce redox cycling.
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CATALYSIS LETTERS
·
2024
·Vol. 154
·期 8
·4378-4388
·
IF 2.3
Zheng Jiahao,Zhang Shule,Zeng Yiqing,Li Mengyu,Li Xiang,Zhong Qin
Simultaneous desulfurization and denitration by using activated coke is one of the most competitive technologies for cleaning low-temperature steel flue gases. The key to denitration performance relies on the regulation of active groups on the catalyst. In this work, the carboxyl and lactone groups with (NH 4 ) 2 S 2 O 8 oxidation and thermal treatment were found to mainly determined the catalytic activity. The results showed that (NH 4 ) 2 S 2 O 8 -treated AC catalyst improved denitration activity at low temperatures, which was attributed to the increase in oxygen-containing groups of the AC, the thermal treatment enhanced the low-temperature activity while reduced the performance in (210–240 ℃). According to the characterization results and conformational relationship analysis, we revealed that the adsorption and activation of NH 3 mainly depended on carboxyl groups during the middle-temperature range (210–240 ℃) NH 3 –SCR. Based on the advantage of middle-temperature denitration activity of modified activated coke, the carboxyl groups on activated coke were the most important active sites for the NH 3 –SCR reaction. Moreover, lactone groups, improved the denitration performance via promoting NO oxidation at low-temperatures range (120–150 ℃). However, the presence of only lactone groups in the 210–240 ℃ is not beneficial for the further promotion for denitration activity. This work initially reveals the decisive role of carboxyl and lactones groups of activated coke for the low-temperature NH 3 -SCR reaction, and guides the industrial arrangement of oxidation-modified AC as denitration catalyst. Graphical
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高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Yaxin Chen,Chao Li,Junxiao Chen,Xingfu Tang
Low-temperature selective catalytic reduction of NO by NH3 (NH3–SCR) is a promising technology for controlling NO emission from various industrial boilers, but it remains challenging because unavoidable deposition of ammonium bisulfates (ABS) in the stack gases containing both SO2 and H2O inevitably results in deactivation of catalysts. Here we developed a stable low-temperature NH3–SCR catalyst by supporting Fe2O3 cubes on surfaces of MoO3 nanobelts with NH4+-intercalatable interlayers, which enables Fe2O3/MoO3 to spontaneously prevent ABS from depositing on the surfaces. Using in situ synchrotron X-ray diffraction, 1H magic angle spinning nuclear magnetic resonance, and temperature-programmed decomposition procedure, the results demonstrate that NH4+ of ABS was initially intercalated in the interlayers of MoO3, leading to a NH4+-HSO4– cation–anion separation by conquering their strong electrostatic interactions, and subsequently the separated NH4+ was consumed by taking part in low-temperature NH3–SCR. Meanwhile, the surface HSO4– separated from ABS oxidized the reduced catalyst during the NH3–SCR redox cycle, concomitant with release of SO2 gas, thereby resulting in decomposition of ABS. This work assists the design of stable low-temperature NH3–SCR catalysts with strong resistance against deposition of ABS.
研究领域:
环境催化
·
材料科学
·
空气污染控制
·
无机化学
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DOI
高影响因子
Nature Communications
·
2026
·
IF 18.1
Guo Xuewen,Hu Yongji,Wu Xiaoyi,Shen Yuesong
H 2 O and SO 2 poisoning of cerium-manganese oxide catalysts remains a critical challenge for low-temperature selective catalytic reduction of nitrogen oxides by NH 3 . Here we show that Ti doping of CeO 2 induces lattice contraction and structural distortion, promoting the generation of oxygen vacancies, active oxygen species, and stable Ce-O-Ti interfaces. These strain-engineered structural modifications enhances surface Lewis acidity and triggers a downshift of the d-band center, collectively improving low-temperature catalytic activity and resistance to H 2 O/SO 2 poisoning. The optimized Ce 8 MnTi 2.5 O x catalyst achieves over 90% nitrogen oxides removal across a 150–335 °C temperature range. Under 5 vol.% water and 100 ppm SO 2 , it maintains over 98% efficiency for 12 h at 210 °C. Furthermore, during stepwise heating from 150 °C to 240 °C with 5 vol.% H 2 O and 200 ppm SO 2 , initial activity suppression below 180 °C is fully reversed at or above 210 °C, demonstrating temperature-driven regeneration. This study introduces a strain-engineering strategy for designing robust catalysts for low-temperature nitrogen oxides removal.
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高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2026
·
IF 12.2
Lin Zheguan,Cao Wanying,Cui Qingyan,Li Tiesen,Bao Xiaojun,Fu Xianzhi,Yue Yuanyuan
Water-induced deactivation of catalysts
under low-temperature
and
high-humidity conditions remains a major challenge for the practical
application of NH 3 -selective catalytic reduction (NH 3 -SCR) technology. Herein, a dynamic Brønsted acid site
compensation strategy based on the heterolytic dissociation of H 2 O is proposed to improve the water tolerance of Cu-based chabazite
catalysts. Following this strategy, a Co-WO 3 /FeCu-SSZ-13
catalyst was rationally designed. Co doping effectively modulates
the d-band center of WO 3 , enabling heterolytic H 2 O dissociation and the in situ generation of hydroxyl
groups that act as Brønsted acid sites, thereby significantly
enhancing NH 3 adsorption and activation. Simultaneously,
preferential utilization of H 2 O for Brønsted acid
site compensation mitigates its competitive occupation of the intrinsic
metal active sites in FeCu-SSZ-13, preserving the NO oxidation pathway
under high-humidity conditions. Therefore, this synergistic regulation
of dynamic compensation of Brønsted acid sites and the release
of active metal sites enables Co-WO 3 /FeCu-SSZ-13 to achieve
a NO x conversion exceeding 90% at 165
° C in the presence of 20 vol % H 2 O. This work highlights
the dual role of H 2 O in simultaneously regulating the acid
and redox cycles, offering a general strategy for designing water-tolerant
NH 3 -SCR catalyst.
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Catalysts
·
2026
·Vol. 16
·期 1
·
IF 4
Xin Liu,Jinshan Zhang,Tao Sun,Hisahiro Einaga,Hajime Hojo,Pengwei Huo
A series of novel Ce-modified MnCoAl layered double oxides (Ce/MCA LDOs) were prepared using solvothermal and impregnation methods for NH3-SCR denitration. Various characterizations, such as X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and H2temperature-programmed reduction (H2-TPR) were used to investigate their structural properties and the mechanism of ammonia selective catalytic reduction (NH3-SCR). The incorporation of Ce was found to effectively integrate into the LDO framework and enhance the catalytic activity over a wide temperature window. Moreover, the thermal stability and resistance of H2O and SO2were evaluated. In situ DRIFTS studies revealed that the reaction follows both the “Langmuir–Hinshelwood” (L–H) and “Eley–Rideal” (E–R) mechanisms. This work provides systematic insights into the design of LDO-based catalysts, demonstrating their potential for practical application in denitration.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xiangsen Xu,Jiangxiao Qiao,Shibo Yu,Jiahao Chen,Yiqing Zeng,Feng Zhang,Zhaoxiang Zhong,Weihong Xing
The rational design of catalysts and the establishment of uniform filter structure are key points in the development of high-performance catalytic filters. To resolve the issue of increased N 2 O concentration in catalysts with high vanadium content at high temperatures, a range of catalytic filters with low vanadium loading were fabricated by partially substituting vanadium in 6VWTi catalysts with transition metals (Mn, Cu, Co and Ce). The experimental results show that the introduction of Ce, which leads to rich surface-adsorbed reactive oxygen species, good redox properties and appropriate surface acidity, thus the 1V5CeWTi/SiC catalytic filter exhibits the highest denitration efficiency (NO conversion ＞90 % at the temperature of 300–500 °C without N 2 O production), presenting significant advantages in contrast to 1VWTi/SiC and 6VWTi/SiC. Furthermore, the preparation technology was optimized to obtain a more uniform structure, which enhanced NH 3 -SCR performance and reduced filter pressure drop. The optimized 1V5CeWTi/SiC also exhibited exceptional resistance to SO 2 + H 2 O and long-term stability for a duration of 200 h at 300 °C, as well as displays a noteworthy efficiency in filtering particulate matter (10 μm SiO 2 ). Therefore, the optimized 1V5CeWTi/SiC catalytic filter holds great potential in the realm of gas purification.
研究领域:
环境工程
·
催化
·
材料科学
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高影响因子
FUEL
·
2022
·
IF 8.035
Xiaodi Li,Shan Ren,Lian Liu,Xiangdong Xing,Lin Chen,Jiangling Li,Jian Yang,Qingcai Liu
The serious deactivation of denitration catalysts caused by heavy metals still a thorny issue in the practical application of selective catalytic reduction of NO x with NH 3 . Herein, we proposed a novel anti-poisoning strategy by designing SO 4 2− /ZrO 2 superacid supported CeO 2 /ZrO 2 catalyst, and the effect of SO 4 2− /ZrO 2 supported CeO 2 /ZrO 2 for PbO-resistance NO x catalytic reduction was investigated. It was worthy to note that the introduction of solid superacid SO 4 2− /ZrO 2 significantly enhanced catalytic performance over the entire temperature range, with an exceptionally high NO x removal efficiency over 98 % during 250–500 °C. When 2 wt% PbO was deposited on the fresh catalyst, the catalytic activity of CeO 2 /ZrO 2 catalyst decreased obviously, while CeO 2 /ZrO 2 -S catalyst can still maintain a higher NO x conversion over 90 % from 275 to 500 °C. The characterization results confirmed that the introduction of solid superacid SO 4 2− /ZrO 2 enhanced the surface acidity and promoted the transformation from Ce 4+ to Ce 3+ . The results of in situ DRIFTS implied that the Eley-Rideal (E-R) mechanism was obeyed over CeO 2 /ZrO 2 catalyst, and both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms were followed over CeO 2 /ZrO 2 -S catalyst in the SCR process. With regard to poisoned catalysts, the NH 3 adsorption was inhibited to some extent, while the reaction mechanism wasn’t changed by PbO poisoning.
研究领域:
催化
·
环境科学
·
化学工程
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高影响因子
危险品化学品经营许可证（带存储）