ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Yunshuo Wu,Xuanhao Wu,Jie Fan,Haiqiang Wang,Zhongbiao Wu
Iron zeolites are promising candidates for mitigating nitrous oxide (N2O), a potent greenhouse gas and contributor to stratospheric ozone destruction. However, the atomic-level mechanisms by which different iron species, including isolated sites, clusters, and particles, participate in N2O decomposition in the presence of CO still remain poorly understood, which hinders the application of the reaction in practical technology. Herein, through experiments and density functional theory (DFT) calculations, we identified that isolated iron sites were active for N2O activation to generate adsorbed O* species, which readily reacted with CO following the Eley–Rideal (E-R) mechanism. In contrast, Fe2O3 particles exhibited a different reaction pathway, directly reacting with CO to generate oxygen vacancies (Ov), which could efficiently dissociate N2O following the Mars-van Krevelen (MvK) mechanism. Moreover, the transformation of iron oxide clusters into undercoordinated FeOx species by CO was also revealed through various techniques, such as CO-temperature-programmed reduction (TPR), and ab initio molecular dynamics (AIMD) simulations. Our study provides deeper insights into the roles of different iron species in N2O-SCR by CO, and is anticipated to facilitate the understanding of multicomponent catalysis and the design of efficient iron-containing catalysts for practical applications.
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
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Zhenhua Zhang,Liping Fan,Weiqi Liao,Feiyue Zhao,Cen Tang,Jing Zhang,Ming Feng,Ji-Qing Lu
Several CeO 2 -CuO/Cu 2 O nanocomposites with different CuO structures were used to identify the structure sensitivity of CuO in the CeO 2 -CuO/Cu 2 O catalyzed CO oxidation. The CO oxidation catalyzed by various CuO-CeO 2 interfacial sites involves a typical Mars-van Krevelen mechanism, in which the CuO-CeO 2 interfaces in the CeO 2 -CuO/c-Cu 2 O (cubes) nanocomposites are more intrinsically active, exhibiting ca. 15 kJ mol −1 lower activation energy than those in the CeO 2 -CuO/o-Cu 2 O (octahedra) and CeO 2 -CuO/d-Cu 2 O (rhombic dodecahedra) nanocomposites at CeO 2 loadings no less than 0.75 wt%. The higher activity is relevant to lower coordinated oxygen ions on CuO/c-Cu 2 O surface and thus better CO reactivity for the CeO 2 -CuO/c-Cu 2 O nanocomposites, which therefore indicates that the active oxygen species on CuO-CeO 2 interface should come from CuO rather than CeO 2 . Moreover, a highly active 13.2 %CeO 2 -CuO/c-Cu 2 O(s) catalyst for CO oxidation is realized on fine Cu 2 O cubes, which thus has high density of active sites.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2017
·
IF 6.198
Yaxin Chen,Zhiwei Huang,Meijuan Zhou,Zhen Ma,Jianmin Chen,Xingfu Tang
The involvement of a great amount of active oxygen species is a crucial requirement for catalytic oxidation of benzene, because complete mineralization of one benzene molecule needs 15 oxygen atoms. Here, we disperse single silver adatoms on nanostructured hollandite manganese oxide (HMO) surfaces by using a thermal diffusion method. The single-atom silver catalyst (Ag1/HMO) shows high catalytic activity in benzene oxidation, and 100% conversion is achieved at 220 °C at a high space velocity of 23 000 h–1. The Mars-van Krevelen mechanism is valid in our case as the reaction orders for both benzene and O2 approach one, according to reaction kinetics data. Data from H2 temperature-programmed reduction and O core-level X-ray photoelectron spectra (XPS) reveal that Ag1/HMO possesses a great amount of active surface lattice oxygen available for benzene oxidation. Valence-band XPS and density functional theoretical calculations demonstrate that the single Ag adatoms have the upshifted 4d orbitals, thus facilitating the activation of gaseous oxygen. Therefore, the excellent activation abilities of Ag1/HMO toward both surface lattice oxygen and gaseous oxygen account for its high catalytic activity in benzene oxidation. This work may assist with the rational design of efficient metal-oxide catalysts for the abatement of volatile organic compounds such as benzene.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Houlin Wang,Shuting Luo,Meisheng Zhang,Wei Liu,Xiaodong Wu,Shuang Liu
Though the catalytic oxidation of CO, NO and soot over CeO 2 could be understood within a similar Mars-van Krevelen-type mechanism, these reactions were likely to be driven by different active phases. In this work, several CeO 2 and Ag/CeO 2 nanorods with different contents of surface oxygen vacancies (V O-s ) and active oxygen species (O x − ) were designed as model catalysts. Their catalytic performance indicated that, CO oxidation was determined by pre-existing ceria V O-s , while O x − participated in NO and soot oxidation directly. Besides, by loading silver onto the high-temperature aged CeO 2 nanorods, Ag/CeO 2 catalysts with high availability of ceria lattice oxygen were obtained, whose low-temperature oxidation activity was proven comparable to that of the platinum catalysts. In this sense, the model designing in this work not only provided methods to find out proper reactivity descriptors, but also conferred low-cost catalysts with high practical potential.
研究领域:
催化
·
材料科学
·
化学工程
·
环境化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Shiqiang Wang,Dan Guo,Meng Han,Yitong Yao,Pengfei Zhang,Xuening Zhang,Jing Lv,Yong Wang,Shengping Wang,Xinbin Ma
Syngas, an extremely meaningful chemical feedstock consisting of hydrogen and carbon monoxide, can be produced through methane dry reforming with carbon dioxide. The extensively utilized Ni-based catalysts usually suffer from coke-induced instability. Herein, we design Ni-CeOx bifunctional catalysts with different proximity and explore the influence of proximity level on anticoking performance. Ni-CeOx bimetallic nanoparticles with intimate contact are precisely regulated through the anchoring strategy of coordination unsaturated Al3+penta, which undergoes the topotactic exsolution of a Ni–Ce–O quasi-solid solution into Ni-CeOx bimetallic nanoparticles. A trend toward easier elimination and even the absence of graphitic carbon is observed with a decreasing spatial distance between Ni and CeOx, which is attributed to the proximity between the dissociation and gasification sites of CHx* intermediates. CHx* species generated at Ni nanoparticles migrated to adjacent CeOx oxygen carriers for Ni-CeOx/Al2O3 catalyst gasification with Ni-CeOx bimetallic nanoparticle interfaces, which undergo the Mars–van Krevelen (MvK) mechanism. The exploration of the Ni-CeOx proximity provides guidance for developing efficient and durable Ni-based DRM catalysts.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Jin Chen,Xuelong Lv,Wenjian Xu,Xiaolan Li,Jing Chen,Hongpeng Jia
The exploit of simple method to synthesize and recover catalyst is meaningful to widespread application of environmental catalysis. Different from traditional knowledge about deposition of Ag cation by Cl anion, we find that Cl anion coordinates with Ru and Ag cations simultaneously to micro-micelles and results in homogeneously alloying of bimetals. The Ru-Ag alloy exhibits a remarkable activity and stability in propane catalytic oxidation at moderate condition, but is still inactivated by extremely-high temperature and humidity due to metal sintering and oxidation as well as support reconstruction. Fortunately, utilization of Cl coordination to extract and combine bimetals at redox condition is proved as a feasible and simple way to regenerate the thermally-inactivated catalyst. With in-situ characterization, the synergic effect between Ru and Ag on propane oxidation obeying Mars-van-Krevelen mechanism is revealed. Through monolith test, the practice application of Ru-Ag catalyst prepared via Cl-assisted method is thought to be promising.
研究领域:
催化
·
环境化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yang Liu,Wei Gao,Hao Zhou,Xianliang Yi,Yongming Bao
Aiming at a simple and effective way to activate the recycled cathode materials from spent Li-ion batteries for air cleaning, LiCoO 2 was synthesized and treated by water for airborne benzene removal. Compared with the pristine sample, whose benzene conversion was ∼20 % at 400 °C, the water-treated one could fulfill 100 % of conversion for 431 ppm of benzene at 300 °C under 120 L g −1 h −1 of space velocity. Furthermore, the water treatment process also worked effectively with the commercialized LiCoO 2 . Characterization results showed that surface oxygen, i.e. , chemically adsorbed oxygen and surficial lattice oxygen, only acted as benzene adsorption sites inert towards benzene oxidation whereas bulk lattice oxygen was reactive for oxidation reaction. Water treatment played two roles in updating the LiCoO 2 surface properties. One was to remove the excessive Li 2 CO 3 and the thus-generated sites could adsorb gaseous oxygen, which was catalyzed to directly oxidize the gas-phase benzene into surface by-products at low temperatures (150−200 °C) following the Elay-Rideal pathway. Another more important role was to expose the bulk lattice oxygen by eliminating the surface oxygen species. The thus-exposed bulk lattice oxygen worked at high temperatures (250−400 °C) and could effectively oxidize the adsorbed benzene following the Mars-van Krevelen mechanism.
研究领域:
材料科学
·
环境工程
·
催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Yang Zou,Xue Li,Yongqi Zhao,Xiaolong Liu,Shaohua Xie,Fudong Liu,Tingyu Zhu
Defect engineering has attracted great attention due to its important role in promoting metal dispersion and regulating catalytic performance. In this study, a gentle method for stabilizing metal single atoms and adjusting the metal coordination environment was proposed, wherein the chemical etching of a Ti–Si oxide composite by NaOH was employed to construct a defect structure. As a conceptual proof, a defective catalyst loaded with 0.1 wt % Pt was synthesized, which exhibited a complete CO oxidation temperature of 200 °C, a significant 70 °C decrease compared to the conventional catalyst. Characterization and theoretical calculations confirmed that Pt existed as single atoms on the defective catalyst, and O2 was adsorbed and activated at Ti3+ defect sites. Notably, the CO oxidation followed the Mars-van Krevelen (MvK) mechanism, resulting in a remarkably low oxygen activation energy barrier of 0.38 eV on the defective catalyst, significantly lower than that on the conventional catalyst (2.48 eV), consistent with its enhanced low-temperature activity. This work provides a promising strategy for the design of efficient and stable low-load noble metal catalysts on oxide-based supports.
✓ 已验证
产品关联
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
Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Zhang Tengfei,Zheng Peng,Gao Jiajian,Liu Xiaolong,Ji Yongjun,Tian Junbo,Zou Yang,Sun Zhiyi,Hu Qiao,Chen Guokang,Chen Wenxing,Liu Xi,Zhong Ziyi,Xu Guangwen,Zhu Tingyu,Su Fabing
Developing high-performance Pt-based catalysts with low Pt loading is crucial but challenging for CO oxidation at temperatures below 100 °C. Herein, we report a Pt-based catalyst with only a 0.15 wt% Pt loading, which consists of Pt–Ti intermetallic single-atom alloy (ISAA) and Pt nanoparticles (NP) co-supported on a defective TiO 2 support, achieving a record high turnover frequency of 11.59 s –1 at 80 °C and complete conversion of CO at 120 °C. This is because the coexistence of Pt–Ti ISAA and Pt NP significantly alleviates the competitive adsorption of CO and O 2 , enhancing the activation of O 2 . Furthermore, Pt single atom sites are stabilized by Pt–Ti ISAA, resulting in distortion of the TiO 2 lattice within Pt–Ti ISAA. This distortion activates the neighboring surface lattice oxygen, allowing for the simultaneous occurrence of the Mars-van Krevelen and Langmuir–Hinshelwood reaction paths at low temperatures.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Xiaoying Zhou,Shiyu Fang,Zihao Hu,Zuliang Wu,Jing Li,Wei Wang,Jiali Zhu,Shuiliang Yao,Erhao Gao
This study introduces a novel catalyst system comprising Pd nanoparticles loaded onto Mn-doped NiO for the efficient oxidation of methane (CH 4 ) at low temperatures. The loading of Pd nanoparticles onto the Mn-doped support has yielded a catalyst with exceptional activity and stability, as evidenced by the lowest T 50 temperature of 276 °C and a CH 4 conversion reaching 97% at 325 °C. The catalyst demonstrates optimized reaction kinetics with the lowest activation energy of 69.2 kJ mol –1 . The catalyst's superior performance is attributed to the synergistic effects of the Pd/Mn-NiO composite, which include a higher Pd 2+ /Pd 4+ ratio, increased adsorptive oxygen concentration (O ads /O total ), and a reduced Ni 3+ /Ni 2+ ratio. These characteristics collectively enhance the catalytic activity for CH 4 oxidation. The Mars-van Krevelen mechanism underpins the oxidation process, with Pd 2+ identified as the principal active site for CH 4 adsorption and dissociation. Diffuse reflectance infrared Fourier transform spectroscopy coupled with mass spectrometry elucidates the pathway of surface reactive oxygen species in the formation of key intermediates, such as formates, and underscores the accelerated decomposition of carbonate facilitated by the Pd modification on the Mn-NiO surface. The findings signify a significant advancement in the development of catalysts for environmental and energy-related applications, particularly in the mitigation of CH 4 emissions.
研究领域:
催化
·
环境科学
·
能源
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Beibei Feng,Chunlan Qin,Ying Shi,Lidong Zhang
Ethanol is extensively used in the transport field as a clean additive and alternative for gasoline in internal combustion engines, although its incomplete combustion inevitably releases harmful species to humans and the environment. Mn-based oxides, one of the most promising materials for catalytic combustion, have attracted considerable interest due to their excellent catalytic performance and low cost. In this work, hydrothermal methods were used to synthesize the different manganese oxides with distinct morphologies (1D-Mn3O4 nanorod, 2D-Mn3O4 nanoplate, and 3D-Mn3O4 nano-octahedron). Meanwhile, catalytic activity over these three catalysts was evaluated for ethanol combustion. The physicochemical properties of these samples were characterized by X-ray diffraction, N2-BET, field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, Raman, and H2-TPR. Among the three catalysts, the Mn3O4 nanoplate exhibited an optimal performance at a space velocity of 60 000 mL g–1 h–1. The apparent activation energy associated with the nanoplate material (25.6 kJ/mol) was lower than that of the 1D-Mn3O4 nanorod (28.9 kJ/mol) and 3D-Mn3O4 nano-octahedron (37.3 kJ/mol). According to characterization results, the Mn3O4 nanoplate catalyst exhibits a small crystal size, large surface area, more exposed (112) facets, abundant Mn4+, and defective structure, contributing to a superior catalytic performance at the high space velocity of 120 000 mL g–1 h–1. In addition, we conclude that the catalytic combustion of ethanol follows the Mars-van Krevelen mechanism based on the kinetic simulation results of experimental data.
研究领域:
化学工程
·
催化
·
材料科学
·
环境科学
✓ 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）