APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
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IF 16.683
Guobo Li,Kai Shen,Ling Wang,Yaping Zhang,Hongqiang Yang,Peng Wu,Bing Wang,Shule Zhang
Development of an efficient synergistic degradation technology to prevent the emission of chlorinated organics and NO x from industrial sources without forming harmful by–products, is a major challenge in environmental chemistry. The designed multi–active center catalyst (PdV/TiO 2 ) showed excellent CB/NO synergistic removal conversion efficiency and target product selectivity. Experimental and DFT calculation results indicated that Pd was the common center for adsorption of CB, O 2 , NH 3 and NO x molecules. The O vacancies (VO x –1 and TiO x –1 ) generated during the CB ring opening process was conducive to adsorption of reaction gas molecules, accelerating CBCO and NH 3 –SCR reaction. The adsorbed NH 3 species would dissociate H protons to provide Brønsted acidic sites necessary for Cl conversion. O vacancies structure was easier to be restored by reoxidation with the participation of NO 2 . Certain synergistic effect in the removal of CB and NO on the multi–active center catalyst surface was found.
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Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Chenxi Wang,Gang Lv,Yunqiang Li,Ye Liu,Chonglin Song
The selective catalytic reduction of nitrogen oxides by methane (CH 4 /NO X -SCR) is a potential technique for the abatement of the NO X emissions from lean-burn GDI engines, due to the excellent thermal stability of CH 4 . This work focuses on the promotion of In/SSZ-13 catalysts by Ce modification for the CH 4 /NO X -SCR performance at high temperatures. A series of In/SSZ-13 and Ce-In/SSZ-13 catalysts were prepared using the wetness impregnation method. The effects of Ce modification on the catalytic performance were analysed in detail using the scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectrum and temperature-programmed desorption/reduction techniques. The results show that the Ce modification significantly enhances the high-temperature activity of the In/SSZ-13 catalysts for the NO X -SCR reaction, especially for the 5 wt% Ce-15 wt% In/SSZ-13 sample which has more than 75% NO X conversion at 390–700 °C. In addition, the Ce modification enhances the water vapor tolerance of the catalyst sample. The Ce modification increases not only the concentration of surface chemisorption oxygen species, but also the relative amount of InO + species which serve as the main active sites for CH 4 activation. Furthermore, the incorporation of Ce into In/SSZ-13 greatly promotes NO X adsorption on the catalyst surface. Most importantly, the Ce modification makes In species well-dispersed on the catalyst surface and thus suppresses the formation of bulk In 2 O 3 species which are more active for the CH 4 non-selective oxidation. The combination of all these effects results in the Ce-In/SSZ-13 samples with the superior catalytic activity .
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CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Guobo Li,Shipeng Ding,Xueyan Hou,Kai Shen,Shule Zhang,Yaping Zhang
Controlling chlorobenzene (CB) and NO x emissions via catalytic oxidation and selective catalytic reduction necessitates high redox performance catalysts, and construction of active centers with multiple adsorption centers towards reactants is prerequisite for developing such catalysts. Herein, the electronic structure and active centers of the PdV/TiO 2 bimetallic catalyst were modulated by Sb modification. The neighboring antimony (Sb) promoted the charge transfer between V and Pd centers, and suppressed the adsorption of SO 2 on active sites, thus accelerating CB/NO x conversion and significantly avoiding the deposition of sulfur species on the active centers, especially the Pd species. The detailed plausible CB/NO x catalytic removal pathway (CB free → CB ads → C 6 H 5 ads + Cl ads + O species (O latt and O ads ) → C x H y O z + Cl ads + Brønsted → CO 2 + H 2 O + HCl on SbPdV/TiO 2 catalyst surface was further established. This research provided a strategy for the development of improved CB catalytic oxidation + selective catalytic reduction (CBCO + SCR) catalysts by tuning the electronic structure of active centers.
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JOURNAL OF CATALYSIS
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2024
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IF 6.5
Ruoyuan Li,Aixia Li,Junhua Li,Yao Wang,Zhiming Liu
Selective catalytic reduction of NO x by CO (CO-SCR) in the presence of O 2 is challenging because in this process CO is prone to being oxidized by O 2 , thus inhibiting NO x reduction by CO. Furthermore, SO 2 typically leads to the deactivation of the CO-SCR catalyst. Herein, a significant promoting effect of SO 2 on Ir/SiO 2 catalyst for the CO-SCR of NO x in the presence of O 2 is reported. In-situ X-ray Absorption Fine Structure (XAFS) and X-ray photoelectron spectroscopy (XPS) analysis showed that SO 2 does not affect the chemical nature of Ir 0 under reaction conditions. However, SO 2 can be oxidized to sulfate and deposit on the catalyst surface. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis demonstrated that the presence of SO 2 can inhibit the CO + O 2 reaction, thus leaving more CO available to reduce NO x over the active Ir 0 sites. As a result, the reduction of NO x is remarkably promoted even in the presence of O 2 and SO 2 .
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VACUUM
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2024
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IF 3.8
Hailin Zheng,Min Zheng,Xianxing Huang,Mingjie Liang,Kang Li
Chemical-looping combustion (CLC) technology is considered a promising combustion method with inherent CO 2 capture. In this study, the sol-gel method and combustion synthesis were employed to produce precursor materials (P) of CuO-based oxygen carriers (OCs). The effects of vacuum drying conditions on both NO x emissions from precursor combustion and oxygen carrier cycle reaction characteristics were investigated. Vacuum-dried precursors emitted less NO x during the precursor calcination process. At a heating rate of 1 °C/min, the vacuum-dried precursors exhibited an average reduction of 24.13 % in NO x emissions compared with those prepared through atmospheric pressure drying. An increased amount of Cu 2 (OH) 3 NO 3 in the precursor results in greater heat release during the self-propagating high-temperature combustion synthesis used to synthesize the oxygen carrier. Furthermore, the complete combustion of the nitrogen-containing precursor leads to a reduction in the emission of NO x . CuO-based OCs exhibited stable redox reactions over 10 cycles. Vacuum drying enhanced CH 4 conversion and CO 2 yield of OC1 by 14.04 % and 13.21 %, respectively, compared to atmospheric pressure drying. The results indicate that the CuO-based OCs obtained through vacuum-dried significantly enhance redox properties. This study shows that vacuum-dried reduces NO x emissions from nitrogen precursors and enhances the cyclic efficiency of OCs from precursor combustion.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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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.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Beilong Lin,Ziyang Guo,Jianhan Li,Gaofei Xiao,Daiqi Ye,Yun Hu
It is a major challenge to achieve effective synergistic reduction of NO x and VOCs in coal-fired flue gas under complex working conditions. In this work, V-Cu bimetallic oxide catalysts with different supports were designed. V1-Cu5 bimetallic oxide supported on TiO 2 showed significantly higher activity for simultaneous toluene oxidation and NO x reduction than that supported on ZSM-5, SiO 2 and γ-Al 2 O 3 . Meanwhile, it exhibited excellent stability and anti-poisoning performance, and could block the formation of toxic polycyclic aromatic hydrocarbons in by-products. Compared with ZSM-5, SiO 2 and γ-Al 2 O 3 , TiO 2 as support was conducive to the formation of abundant acidic sites and oxygen vacancies. In addition, the strong interaction between the metal active sites and TiO 2 accelerated the electron transfer from Cu to adsorbed O 2 , thus promoting the formation of active O 2− . This work can provide guidance for the development of catalysts designed for the simultaneous catalytic removal of NO x and VOCs.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2022
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IF 5.876
Yang Zhang,Baihe Sun,Lin Jiang,Jiahui Fan,Fangjie Qin,Zhuo Liu,Jue Wang,Kan Kan,Keying Shi
A facile polymer heat treatment and reflux method are used for developing growth of flower-like BiOCl (BiOCl NFs) on 3D honeycomb-like N-doped graphitic carbon (N-GC) to form BiOCl/N-GC composites. The N-GC hierarchical structure effectively heightened the dispersion of BiOCl NFs, which increased the contacted area for the NO x gas molecule. Benefiting from the hierarchical structure, the (102) plane of BiOCl has a suitable adsorption energy for NO x , synergistic effect of large specific surface area and mesopores of N-GC, the formation of p-p heterojunctions , Bi–C interfacial bond, N-doping and the role of chemisorbed oxygen. The BiOCl/N-GC composites have satisfactory response and selectivity for NO x gas at room temperature. It reveals an exceptionally excellent response and response time of 52.54 and 3.2 s for NO x gas. It also exhibits a low detection limit (10 ppb) and a long-stability of 12 weeks. Thus, the BiOCl/N-GC nanocomposites are one of the most potential materials in gas sensor.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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IF 9.7
Jianwen Lai,Hongbo Qi,Yunfeng Ma,Xiaoqing Lin,Xiaoying Wang,Zhongkang Han,Heidelore Fiedler,Xiaodong Li
Cerium is widely used as a modifier to enhance the catalytic performance of the selective catalytic reduction (SCR) catalysts due to its exceptional low-temperature properties. However, the effects of different cerium precursors on catalytic performance remains unclear. In this study, VO x -WO x /TiO 2 catalysts are modified using Ce(NO 3 ) 3 ·6H 2 O (cata-N), CeO 2 (cata-O), and Ce(OH) 4 (cata-OH), and their synergistic removal of NO x and chlorobenzene (CB), as well as their resistance to water and sulfur poisoning, were systematically investigated. Among the tested catalysts, cata-N demonstrated superior CB (45.0–93.3 %) and NO x (31.9–90.37 %) removal efficiencies under synergistic conditions, along with excellent water resistance (T 90 = 193 °C with 5 % H 2 O). In contrast, cata-OH exhibited the highest sulfur resistance, maintaining a denitrification efficiency of 20 % after 10 h of sulfur exposure, compared to 9 % for cata-N and 8 % for cata-O. Characterization revealed that Ce(NO 3 ) 3 ·6H 2 O improved cerium dispersion, leading to enhanced the redox properties and acidity (especially Brønsted acid sites (BAS)) in cata-N. Density functional theory (DFT) calculations and In-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy ( In-situ DRIFTS) results revealed that the well-dispersed cerium atoms contributed additional BAS in the form of Ce–OH, while also forming Ti–O–Ce bonds. These Ti–O–Ce bonds facilitated the formation of Ti–OH on the TiO 2 surface. Ti–OH significantly enhanced the adsorption of NH 3 and CB, thereby promoting both the NH 3 -SCR and CB oxidation processes. This study offers new insights into the role of cerium precursors and provides a practical strategy for tuning BAS of catalysts in multiple pollutants removal.
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CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Peng Zhang,Yongfang Rao,Yu Huang,Meijuan Chen,Tingting Huang,Wingkei Ho,Shuncheng Lee,Junbo Zhong,Junji Cao
The inevitable amorphous Bi 2 O 3 on the surface of plasmonic Bi nanospheres serving as the recombination center of hot electron-hole pairs, hindered the transfer of photo-generated hot electrons and production of reactive oxygen species (ROS) seriously. In this study, Bi@amorphous Bi 2 O 3 was transformed to Bi@crystal Bi 2 O 2 CO 3 by secondary hydrothermal reaction. Bi@Bi 2 O 2 CO 3 core–shell photocatalyst exhibited higher visible-light catalytic activity (34.1%) than Bi@Bi 2 O 3 did (12.3%) in terms of NO x removal. Photoelectrochemical, surface photovoltage spectroscopy spectra and Kelvin probe force microscopy measurement results indicate that Bi 2 O 2 CO 3 shell reduced the transmission resistance of hot electrons excited from Bi core. O 2 -TPD, trapping experiments and density functional theory further confirmed that the transferred hot electrons were a help for ROS generation and •O 2 − radicals were the major contributor. This study not only addresses the unsettled issue of surface amorphous Bi 2 O 3 , but also provides a facile method to transform the amorphous shell to crystal phase of core–shell photocatalyst and new insights into the hot electrons separation and the formation of main ROS over the surface crystal transition of plasmonic Bi.
研究领域:
材料科学
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环境科学
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化学
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ACS Catalysis
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2026
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IF 13.6
Xinhao Bai,Peng Wu,Jianjun Chen,Chang Wang,Jinxing Mi,Xiaoping Chen,Feifan Huang,Junhua Li
The challenge of tackling atmospheric pollutants and the demand for low-carbon environmental technologies have imposed urgent requirements on the control of CO and NOx pollutants. Synergistic catalytic treatment is regarded as the most ideal emission reduction technique, with the difficulty lying in simultaneously enhancing catalytic activity and resolving competitive adsorption. In this work, the Cu component was incorporated into the CeTiO2 catalyst. The optimized Cu2/CeTiO2 catalyst achieved over 90% conversion for both CO and NOx across a broad temperature range of 225–325 °C. Characterization and theoretical calculations demonstrated that Cu doping decreased the valence state of Ce and Ti sites, thereby enhancing lattice oxygen activation and migration ability. The increased CO adsorption also contributed to the elevated CO oxidation activity. The broadening of the simultaneous removal temperature range was achieved by eliminating competitive adsorption of reactants. Specifically, the competitive adsorption between NH3 and CO was mitigated after Cu doping. NO was primarily adsorbed at the Ce and Ti sites, while Cu was engineered as the CO capture site. This substantially reduced the competitive adsorption between the two reaction atmospheres, enabling simultaneous removal of both pollutants. This research offers a reliable approach and catalyst construction strategy for the simultaneous removal of CO and NOx, thereby advancing the development of pollution reduction and carbon mitigation technologies.
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JOURNAL OF CATALYSIS
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2021
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IF 7.92
Yonglong Li,Senyou Yang,Honggen Peng,Wenming Liu,Yangyang Mi,Zheng Wang,Changjin Tang,Daishe Wu,Taicheng An
Manganese (Mn)-based mixed oxides are considered the most efficient catalysts for low-temperature ammonia selective catalytic reduction of nitrogen oxides (NO x ) (NH 3 -SCR of NO x ). Water resistance and sulfur tolerance, especially the SO 2 tolerance of Mn-based catalysts, are the main obstacles preventing their practical application. Therefore, in this study, a series of cobalt (Co)-doped MnFeO x ternary mixed oxides catalysts with a hierarchically ordered structure (Hierc-MnFe 1-δ Co δ O x , δ = 0.2, 0.4 and 0.6) were developed and applied for NH 3 -SCR of NO x at low temperature. Compared with Hierc-MnFeO x , Hierc-MnFe 1-δ Co δ O x catalyst exhibited enhanced low-temperature activity and a broadened temperature window (NO x conversion above 80% was between 90 and 343 °C over Hierc-MnFe 0.6 Co 0.4 O x ), as well as better H 2 O resistance and SO 2 tolerance. The enhanced low-temperature activity was attributed to a larger amount of active oxygen species, a higher proportion of Mn 4+ , Fe 3+ and Co 3+ content, and the improvement of surface acidity, which can facilitate the adsorption and activation of NO and NH 3 . Additionally, the Hierc-MnFe 0.6 Co 0.4 O x catalyst exhibited superior soot tolerance due to its special hierarchically ordered architecture. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) revealed that the Co-modified Hierc-MnFe 1-δ Co δ O x ternary oxide catalyst could efficiently protect nitrate species on Hierc-MnFe 0.6 Co 0.4 O x from the poisoning effect of SO 2 , thereby boosting its SO 2 tolerance. This study provides a good candidate for low-temperature de NO x application with enhanced SO 2 and soot tolerance.
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