JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Minghu Zhao,Junyi Chen,Fei Wu,Yungang Wang,Kai Chen,Chao Xiong,Rongshu Zhu
Rationally designing catalysts suitable for flue gas purification at low temperatures and unraveling the anti-poisoning mechanism at the atomic level remain challenges. Here, a highly dispersed Ni-doped MnO x catalyst (Ni 0.1 Mn 0.9 O x ) was constructed and applied for selective catalytic reduction (SCR) of nitrogen oxides (NO x ). The long-term stability of Ni 0.1 Mn 0.9 O x is up to 80% (180 ℃) after 18 h under SO 2 and H 2 O conditions. This is due to the fact that the highly dispersed Ni atoms enhance the redox and surface acidity of MnO x , and modulate the electronic structure of the active Mn sites. The denitrification reaction on Ni 0.1 Mn 0.9 O x mainly follows the Eley-Rideal mechanism. The anti-poisoning mechanism is that the introduction of Ni weakens the electron transfer between the Mn site and SO 2 , thereby inhibiting the adsorption of SO 2 . In particular, the H 2 O adsorbed on the Ni sites is decomposed to replenish the depleted Brønsted acid sites, which facilitates the adsorption of NH 3 . However, an excess of H 2 O can have an inhibitory effect. In addition, the mesoporous structure may increase the mass transfer rate and reduce the accumulation of harmful substances. This study provides viable insights for the design of SCR catalysts with excellent anti-poisoning ability.
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
FUEL
·
2024
·
IF 6.7
Dou Chuanchuan,Liu Yuling,Shu Hao,Li Shuaishuai,Shi Qiyuan,Luo Xinzeng
Metal oxide catalysts derived from MOFs can inherit the excellent performance from their parent MOFs, possess abundant surface defects and high stability, and have attracted widespread interest in multiphase catalysis. In this study, we used Mn-MOF as a precursor and systematically investigated the evolution of MnO x catalysts by setting different calcination temperatures and times. XRD, SEM, TEM, Fourier transform infrared spectroscopy (FTIR), N 2 adsorption–desorption analysis, XPS, H 2 -TPR, CO 2 -TPD, electrochemical characterization, and other methods were used to investigate the structural characteristics, microstructure, surface properties, and photoelectric properties of the catalysts. The catalytic performance of the catalysts was also investigated through photocatalytic carbon dioxide hydrogenation reduction tests. Research has shown that calcination temperature and time have a significant impact on the phase structure and surface properties of MnO x , and the physicochemical properties of derived MnO x can be controlled by controlling calcination temperature and time. Among them, MnO x -500 has a wider light absorption range, better electron transfer performance, richer oxygen vacancies, and excellent separation performance of photo generated charge carriers, resulting in higher photocatalytic CO 2 hydrogenation and reduction performance. Its CO yield and selectivity reached 7420 μmol/g/h and above 99 %, respectively. This study provides valuable references for the preparation, optimization, and utilization in CO 2 photothermal catalytic conversion of MnO x catalysts derived from MOFs.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2016
·
IF 4.012
Peng Sun,Rui-tang Guo,Shu-ming Liu,Shu-xian Wang,Wei-guo Pan,Ming-yuan Li
A series of MnEuOx catalysts were prepared by the co-precipitation method and used for selective catalytic reduction of NOx with NH 3 . It was found that the modification of MnOx catalyst by Eu with a Eu/Mn molar ratio of 0.1 could greatly enhance its SCR activity and broaden its operating temperature window, accompanied by good resistance to SO 2 and H 2 O. From the characterization results of N 2 adsorption, XRD, XPS, H 2 -TPR, it could be concluded that the larger surface area resulted from the inhibited crystallization of MnOx, the enrichment of surface Mn 4+ and chemisorbed oxygen, and the higher reducibility all made a contribution to the high SCR activity of MnEuOx-0.1 catalyst. Furthermore, the results of in situ DRIFTS study revealed the NH 3 -SCR reactions over MnOx and MnEuOx-0.1 were mainly controlled by L-H mechanism (<150 °C) and E-R mechanism (>150 °C) respectively, and the contribution of E–R mechanism became more important with increasing reaction temperature. The enhanced NO oxidation and NH 3 adsorption should be mainly contribute to the distinguished SCR performance of MnEuOx catalyst in the lower temperature range (<150 °C) and higher temperature range (>150 °C) respectively.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Lei Wang,Xin Zhang,Yonggang Sun,Yulong Ma,Min Xu,Juan Zhang,Yingbo Zhu,Li Zhu,Song Qiao,Jing Ma,Jinpeng Wei,Feng Lin
Environmental H 2 O has a significant effect on the reaction mechanism and process of VOC oxidation, of which the intrinsic mechanism is hardly reported. Herein, a series of PtCu δ -MnO x catalysts with different strong metal-supported interactions were constructed by replacing some Pt species with Cu species. Among them, the PtCu 3 -MnO x catalyst exhibited superior catalytic performance (T 90 = 170 ℃), high water resistance, and long-term stability. Furthermore, in-situ diffuse reflectance infrared Fourier transform spectroscopy ( in-situ DRIFTs) showed that the acetone oxidation followed synergistic cooperation of the Langmuir-Hinshelwood (L-H) and Mars van Krevelen (MvK) mechanism. Acetone oxidation over PtCu 3 -MnO x occurred via the L-H mechanism producing surface acetate and formate species intermediate. Above 100 °C, adsorbed acetone (i.e., acetate and formate species) reacts with MnO x lattice oxygen according to the MvK mechanism to form CO 2 and H 2 O. When water vapor was present, the L-H mechanism was impaired, inhibiting the deep oxidation of acetone. This research provides an in-depth exploration of how water vapor impacts the reaction mechanism of acetone oxidation. It offers valuable insights for creating dependable catalysts suitable for use in various industrial settings.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Zhiqiang Zhang,Baiyun Zhu,Lu Xu,Yan Wang,Jiawei Ji,Wang Song,Meilin Tao,Changjin Tang,Lin Dong
Alkali metal poisoning represents a formidable challenge for the effective utilization of ammonia selective catalytic reduction (NH3–SCR) technology. Herein, we propose a versatile strategy to radically circumvent the deactivation effect from alkali metals via regulated activation of surface NOx species. Activity test showed that after physical mixing with a series of zeolites (ZSM-5, MOR, and SAPO-34), the activity of the K-poisoned CeO2–MnOx catalyst achieved complete recovery, and the observed NO conversion was found to be even superior to that of the fresh catalyst. Mechanism analysis from in situ DRIFTS and TPSR revealed that K deposition shut off the transformation of surface NOx from chelating bidentate nitrites to bidentate nitrates (both bridging and chelating bidentate nitrates), leading to catalyst deactivation. Zeolite coupling introduced labile NO+ species, which interacted facilely with the chelating bidentate nitrites to generate chemically reactive bidentate nitrates, enabling a thorough regeneration of NH3–SCR performance. In addition to CeO2–MnOx, this strategy was also found to be valid for a variety of NH3–SCR catalysts, demonstrating great potential in reversing alkali metal poisoning.
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
CHEMICAL ENGINEERING SCIENCE
·
2021
·
IF 4.311
Tingting Qi,Linyu Zhou,Yingjiao Li,Guang-Wen Chu,Yong Luo,Jie Shi,Haikui Zou,Bao-Chang Sun
Oxygen vacancy (OV) plays a significant role in the catalytic performance of oxidation catalysts. Herein, ZSM-5@MnO x catalyst with abundant OVs was firstly prepared by in-situ growth method. The prepared catalyst exhibits good catalytic activity for the selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) with ~100% BA conversion and ~100% BAD selectivity within 3 h. We have proved that the OV in ZSM-5@MnO x catalyst is the main active site for the BA oxidation. Besides, the OV formation mechanism is proposed based on the influences of modified ZSM-5 supports on OVs. Results show that sodium ions in ZSM-5 are conducive to enhancing the coating of MnO x on supports, and protons in ZSM-5 are beneficial for the formation of OVs by dehydrating with hydroxyls on MnO x . Based on the mechanism, we further enrich OVs by the deep dehydration to improve its catalytic performance. This work provides a novel route for the design of OVs in the ZSM-5@MnO x catalyst.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 15
·5616-5622
·
IF 8.262
Bingquan Xia,Teng Liu,Wei Luo,Gongzhen Cheng
Safe and efficient storage of hydrogen is the key issue for the hydrogen economy. Hydrazine monohydrate is regarded as a potential hydrogen carrier. Herein, we report a facile synthesis of NiPt–MnOx supported on nitrogen-doped porous carbon (NPC) derived from annealing metal–organic frameworks (MOFs) at different temperatures in Ar. Interestingly, the obtained (Ni3Pt7)0.5–(MnOx)0.5/NPC-900 exhibits superior catalytic activity toward dehydrogenation of an alkaline solution of hydrazine, with initial turnover frequency values of 706 and 120 h−1 at 323 K and room temperature, respectively. This excellent catalytic performance may have resulted from the synergistic electronic effect of NiPt and MnOx, the small size and high dispersion of NiPt–MnOx nanocatalysts, NPC as an excellent support with large pore volume, high surface area, high nitrogen content, electrical conductance, and also the high density of the metal-N active sites between NiPt–MnOx and NPC.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2016
·Vol. 118
·期 2
·605-619
·
IF 1.265
Wang Lei,Zhang Chuanhui,Huang He,Li Xuebing,Zhang Wei,Lu Mohong,Li Mingshi
MnO
x
catalysts were contrastively prepared by an alkali-promoted redox precipitation strategy (MnO
x
-RP) and a conventional citrate sol–gel method (MnO
x
-SG), and tested for the catalytic oxidation of toluene, where MnO
x
-RP exhibited higher catalytic activity, excellent catalytic durability under dry conditions and good regeneration ability under humid conditions. The characterizations results indicated that different crystalline phases but similar textual properties (specific surface area, porosity and morphology) were observed over MnO
x
-RP and MnO
x
-SG catalysts, while MnO
x
-RP presented significantly higher low-temperature reducibility and average oxidation state of Mn as well as higher abundance of surface adsorbed oxygen species compared with MnO
x
-SG, thus beneficially resulting in its superior catalytic activity in the reaction.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Xiao Zhang,Xueying Zhang,Cai Liang,Feng Shen,Boxiong Shen
Water poisoning remains a significant challenge for Mn-based catalysts in the purification of low-temperature industrial flue gas. In this study, a water-resistant catalyst, Cu-doped MnO x dispersed on a flower-like hollow sphere carrier (Cu 0.1 Mn 1 -Al 2 O 3 (NF)), was developed. The introduction of 5 % water vapor into simulated flue gas reduced the o-xylene oxidation efficiency of the unmodified MnO x /γ-Al 2 O 3 catalyst by 20 %, whereas Cu 0.1 Mn 1 -Al 2 O 3 (NF) exhibited only a 5 % reduction, and it shows a water resistance surpasses those of most of the reported MnO x catalysts. Upon water vapor withdrawal, Cu 0.1 Mn 1 -Al 2 O 3 (NF) showed a 2 % irreversible efficiency loss, compared to 9 % for MnO x /γ-Al 2 O 3 . Mechanistic studies highlight the role of the flower-like morphology in reducing hydrogen-bonded H 2 O and the primary contribution of Cu + doping in suppressing –OH generation on metal sites, likely due to weakened H 2 O dissociation at Mn-Ov-Cu oxygen vacancies. Additionally, Cu 0.1 Mn 1 -Al 2 O 3 (NF) has improved water desorption capability evidenced by 8 °C lower endothermic temperature for H 2 O volatilization than that of MnO x /γ-Al 2 O 3 . Furthermore, a H 2 O-involved Mars-van Krevelen (MvK) mechanism was proposed to explain the ∼ 2 % irreversible efficiency reduction for Cu 0.1 Mn 1 -Al 2 O 3 (NF) in wet gas − attributed to H 2 O dissociation at oxygen vacancies hindered lattice oxygen replenishment. Based on this mechanism, an air-purging regeneration protocol was developed to enhance the catalyst’s operational stability under wet flue gas conditions.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Tian Gu,Chengzhi Wang,Denghui Chen,Mengmeng Han
Modulating the physicochemical properties of catalysts through the construction of special crystal structures or microscopic morphology provides new insights for developing high-performance low-temperature denitrification catalysts. This paper explores the effect of morphology structure on catalyst performance and identifies the dominant driving factors. The catalyst activity sequence was found to be MnO x spiny nanospheres (Mn-SNS) > MnO x nanowires (Mn-N) > MnO x nanospheres (Mn-NS) > MnO x nanoparticles (Mn-P). Among these, the Mn-SNS catalyst prepared by the hydrothermal method exhibited the best catalytic activity and the good resistance to water and sulfur. It achieved over 70% NO x conversion at 150 °C, and maintained 100% at 200–350 °C. In the presence of SO 2 and H 2 O, the NO x conversion was maintained at 87%. The spherical structure consisting of nanospikes provides the Mn-SNS catalysts with a large specific surface area, more (Mn 4+ +Mn 3+ ), abundant acid sites, and stronger reducibility, thus exhibiting excellent performance through the "fast-SCR" pathway. It also inhibits oxide crystallization and provides more sites for the adsorption activation of NO x and NH 3 . The nanowire structures can provide a large specific surface area and a high concentration of Mn 3+ and Mn 4+ for MnO x catalyst. Characterization analyses revealed that the specific surface area, the ratio of (Mn 4+ +Mn 3+ )/Mn, and the number of Lewis acid sites (L-NH 3 ) are the most important factors affecting the catalytic activity. This present empirical analysis provides new ideas for designing high-performance catalysts with a large specific surface area.
研究领域:
环境科学
·
催化科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 8
·752
·
IF 4
Yulin Sun,Yiwei Zhang,Yong He,Wubin Weng,Yanqun Zhu,Zhihua Wang
Metal–organic frameworks (MOFs) have become a hot topic in various research fields nowadays. And MOF-derived metal oxides prepared by the sacrificial template method have been widely applied as catalysts for pollutant removal. Accordingly, we prepared a series of MOF-derived MnOxcatalysts with diverse morphologies (rod-like, flower-like, slab-like) via the pyrolysis of MOF precursors, and the as-prepared MnOxcatalysts demonstrated superior performance compared to the one prepared using the co-precipitation method. MnOx-II, with a flower-like structure, exhibited excellent activity for formaldehyde (HCHO) catalytic ozonation at room temperature, reaching complete HCHO conversion at O3/HCHO of 1.5 and more than 90% CO2selectivity at an O3/HCHO ratio of 2.5. On the basis of various characterization methods, it was clarified that the enhanced catalytic performance of MnOx-II benefited from its larger BET surface area, abundant oxygen vacancies, better redox ability at lower temperature, and more Lewis acid sites. The H2O resistance and stability tests were also conducted. Furthermore, DFT calculations substantiated the enhanced adsorption of HCHO and O3on oxygen vacancies, while in–situ DRIFTS measurements elucidated the degradation pathway of HCHO during catalytic ozonation through detected intermediates.
研究领域:
环境催化
·
材料科学
·
污染物去除
·
纳米材料
·
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）