JOURNAL OF CHEMICAL SCIENCES
·
2022
·Vol. 134
·期 2
·1-11
·
IF 2.15
Yu Miao,Ji Shuai,Li Zhifang,Song Kun,Li Yueyu,Yang Jian,Yang Changlong
A simple ion-exchange method is used to prepare Mn and Co-supported TNU-9 denitration catalyst for NH 3 -SCR. The denitration activity and H 2 O/SO 2 resistance performance of the catalyst are systematically studied. The denitration activity test exhibits that the NO x removal rate of Mn-Co/TNU-9 is higher than that of Mn/TNU-9 and Co/TNU-9, the NO x removal rate is greater than 90% and the N 2 selectivity is greater than 99% in the range of 150 ~ 450 °C. It is because the redox cycle of Mn 4+ + Co 2+ ↔ Mn 3+ + Co 3+ improves the redox performance of the catalyst, which is conducive to the conduction of electrons, and then accelerates the oxidation of NO to NO 2 to produce a "fast SCR" reaction, and finally optimizes the overall SCR performance. Furthermore, the change is not significant for the catalytic activity over Mn-Co/TNU-9 in the presence of water. However, the sulfur resistance is poor at low temperatures due to the presence of ammonium bisulfate. It also has excellent catalytic stability. Therefore, supported TNU-9 catalysts will have a good development prospect in denitrification. Graphical abstract Mn-Co co-doped TNU-9 catalyst was successfully synthesized by simple ion exchange method and applied in the NH 3 -SCR. The results show that Mn-Co/TNU-9 catalyst has an excellent wide activity window in a wide temperature range of 150-450°C (NO x conversion over 90%), which is because Mn+Co 2+ ↔Mn+Co improves the redox performance and facilitates the electron transfer, which further accelerates the oxidation of NO into NO 2 that could result in the “Fast SCR” reaction. The synergistic effect between Mn and Co bimetallic can also improve activity. Moreover, Mn-Co/TNU-9 has very good catalytic stability.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2016
·
IF 2.208
Jixing Liu,Fuhong Yu,Jian Liu,Lifeng Cui,Zhen Zhao,Yuechang Wei,Qianyao Sun
A series of meso-microporous Cu-SAPO-34 catalysts were successfully synthesized by a one-pot hydrothermal crystallization method, and these catalysts exhibited excellent NH 3 -SCR performance at low temperature. Their structure and physic chemical properties were characterized by means of X-ray diffraction patterns (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N 2 sorption-desorption, nuclear magnetic resonance (NMR), Inductively Coupled Plasma-Atomic Emission spectrometer (ICP-AES), X-ray absorption spectroscopy (XPS), Temperature-programmed desorption of ammonia (NH 3 -TPD), Ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS) and Temperature programmed reduction (TPR). The analysis results indicate that the high activities of Cu-SAPO-34 catalysts could be attributed to the enhancement of redox property, the formation of mesopores and the more acid sites. Furthermore, the kinetic results verify that the formation of mesopores remarkably reduces diffusion resistance and then improves the accessibility of reactants to catalytically active sites. The 1.0-Cu-SAPO-34 catalyst exhibited the high NO conversion (> 90%) among the wide activity temperature window in the range of 150–425°C.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Chaoqun Bian,Fang Chen,Ling Zhang,Weiping Zhang,Xiangju Meng,Stefan Maurer,Daniel Dai,Andrei-Nicolae Parvulescu,Ulrich Müller,Feng-Shou Xiao
High silica chabazite zeolite (CHA) is very important for selective catalytic reduction of NOx with ammonia (NH 3 -SCR), but its synthesis is time-consuming under conventional hydrothermal conditions (160 °C for 90–120 h). Herein, we report a novel strategy for highly efficient synthesis of CHA zeolite by means of fast crystallization at high temperatures in the absence of water solvent (240 °C for 1.5 h). X-ray diffraction, N 2 -adsorption isotherms, inductively coupled plasma, scanning electron microscopy, 29 Si and 27 Al MAS NMR, as well as thermogravimetry-differential thermal analysis suggest that the samples have high quality. This concept significantly enhances the space-time yields (STY) for CHA zeolite prepared from high-temperature synthesis in the absence of water solvent (almost two orders of magnitude higher than those of conventional hydrothermal synthesis). Moreover, compared with hydrothermal synthesis, the samples obtained from fast crystallization at higher temperatures (Si/Al = 12, 2.0% Cu loading) shows enhanced catalytic performance at 350–550 °C in NH 3 -SCR.
研究领域:
材料化学
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催化化学
·
无机合成
·
环境化学
·
能源化学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2025
·Vol. 155
·期 10
·322
·
IF 2.4
Li Xuewen,Li Yaru,Wang Menglin,Wang Can,Jing Wenxian,Fang Lisheng,Hu Yonghua,Liang Yundong,Wang Xianbiao
Manganese oxides (MnO x ) catalysts are promising for low-temperature ammonia-selective catalytic reduction (NH₃-SCR), however, the limited N₂ selectivity and the narrow operational temperature range remain challenges. To address these issues, we developed a method involving impregnation doping and high-temperature calcination to hybridize Mn₂O₃ with iron lattice and oxide. This hybrid catalyst maintains a NO x conversion rate above 90% within the broad temperature window of 175–300 °C, while achieving N₂ selectivity above 99%. The as prepared Fe-Mn (0.15) exhibits spherical morphology with Fe and Mn uniformly distributed. Through XPS, XAFS, H₂-TPR, NH₃-TPD and catalytic activity tests, we verified that lattice iron doping slightly reduces the reducibility of the catalyst and enhances low-temperature activity (100–200 °C) by increasing Lewis acid sites. Meanwhile, the Fe₂O₃ domains promote high-temperature performance (200–300 °C) by enriching surface oxygen species and Bronsted acid sites. These synergistic effect regulates both the acidic and redox properties of the catalyst, facilitating NH 3 activation while suppressing over-oxidation, leading to superior NH 3 -SCR performance. Furthermore, in situ DRIFTS measurements confirmed that the reaction proceeds predominantly via a Langmuir-Hinshelwood (L-H) mechanism. This work reveals the synergistic effects of Fe lattice doping and Fe₂O₃ composite on MnO x , offering new insights for developing advanced low-temperature catalysts. Graphical
研究领域:
催化化学
·
环境科学
·
材料科学
·
能源化学
·
大气污染控制
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2025
·Vol. 156
·期 1
·21
·
IF 2.4
Yang Jihui,Shi Minghao,Zheng Jiahao,Zhang Shule,Zhong Qin
Ammonia Selective Catalytic Reduction (NH₃-SCR) is highly effective for nitrogen oxide (NO x ) removal, yet its low-temperature activity remains a key limitation for broader applications. We developed an innovative series of microporous N, O-codoped carbon catalysts (NOAC-x) that facilitate the fast SCR reaction. Results demonstrate that the synergy between catalyst micropore structure and surface functional groups governs denitrification performance: Low-temperature calcination induces pore blockage by nitrogen-containing groups (pyridinic N), reducing specific surface area and weakening NH₃/NO adsorption capacity.Moderate calcinatio promotes partial decomposition of nitrogen groups, optimizing the micropore structure while preserving active sites such as carboxyl groups and pyridinic N, thereby significantly enhancing catalytic activity.High-temperature calcinatio triggers pore collapse and decomposition of active groups, degrading performance.NOAC-600 achieved 95% NO x conversion at 120 °C and exhibited merely a 2% activity decline during a 108-hour stability test. This work provides theoretical guidance for designing microporous N, O-dual-doped carbon-based catalysts and underscores the critical importance of micropore structure and surface chemistry optimization in low-temperature SCR technology. Graphical
研究领域:
环境催化
·
材料化学
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大气污染控制
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碳材料科学
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表面化学
✓ 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）