CRYSTENGCOMM
·
2018
·Vol. 20
·期 43
·7020-7029
·
IF 3.304
Xuehui Huang,Hongyun Pan,Kui Chen,Zhilin Yin,Jing Hong
A molten salt method has been used to prepare porous La0.8Sr0.2Mn1−xCuxO3 (0 ≤ x ≤ 0.4) (LSMC-X) microspheres and La0.8Sr0.2MnO3 (LSM) nanocubes using spherical and cubic MnCO3 as templates, respectively. XRD patterns showed a single perovskite phase when the Cu content was less than x = 0.3. SEM and TEM images indicated that the porous microspheres comprised many aggregated nanoparticles, while the nanocubes were solid with a smooth surface. LSM and LSMC-0 samples both possessed high surface areas (63.5045 and 49.6504 m2 g−1, respectively). Furthermore, the CO conversions showed that LSMC-0.2 had the best catalytic activity (T50 = 83.63 °C, T90 = 97.40 °C) and good stability. XPS analysis confirmed that Cu2+ doping induced Mn4+ formation and slight changes in the oxygen species, leading to different catalytic activity. Owing to their facile synthesis and high catalytic performance, we propose that these porous spherical La0.8Sr0.2Mn1−xCuxO3 (0 ≤ x ≤ 0.4) and nanocubic La0.8Sr0.2MnO3 catalysts are promising candidates for CO oxidation.
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
Materials Today Nano
·
2021
·
IF 8.109
B. Yi,H. Zhao,L. Cao,X. Si,Y. Jiang,P. Cheng,Y. Zuo,Y. Zhang,L. Su,Y. Wang,C.-K. Tsung,L.-Y. Chou,J. Xie
Mixed-metal metal-organic frameworks (MM-MOFs) contain more than one type of metal node, which can improve or even introduce new features compared with the single metal frameworks. Traditionally, most of the MM-MOFs are synthesized by solution method which requires all the metal ions to form stable coordination with the ligand in a single framework and therefore limits the choice of the metal ions. In this work, Pt-doped Zn-MOF-74 (PtZn-MOF-74) has been prepared through a mechanochemical conversion approach from Pt-doped ZnO (Pt–ZnO) directly. The absence of a large quantity of solvent limits the solvation and diffusion of growth species during the mechanochemical conversion and therefore prevented the agglomeration of Pt dopants in PtZn-MOF-74. CO oxidation was used to evaluate the catalytic performance of the prepared MM-MOFs. Compared with inert Zn-MOF-74, PtZn-MOF-74 with unsaturated coordinated Pt at elevated temperature can act as the active sites to catalyze CO oxidation reaction. This study provides a novel design strategy for the synthesis of MM-MOFs with extended functionalities.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2024
·
IF 3.5
Zihao Hu,Xiaoying Zhou,Tiantian Zhang,Zuliang Wu,Jing Li,Wei Wang,Erhao Gao,Jiali Zhu,Shuiliang Yao
Aiming at the problem of the poor performance of an Mn-MOF-74-derived Mn3O4 catalyst in low-temperature carbon monoxide (CO) oxidation, copper (Cu) and cerium (Ce) elements were used to modify the Mn3O4 catalyst to improve its performance in low-temperature CO oxidation. According to the results of catalytic performance testing, the CO oxidation activity of the Cu0.3Mn2.7O4 catalyst was significantly improved compared with that of the pristine Mn3O4 catalyst, when a CO conversion rate of 90% was achieved at 118 °C. According to X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller analyses, the (Mn2+ + Mn3+)/(Mn2+ + Mn3+ + Mn4+) ratio and the Oads/Ototal ratio increased after Cu doping, indicating promoted oxygen vacancy generation. In addition, the increased specific surface area was beneficial for the adsorption of reactant molecules and the exposure of active sites. According to H2-temperature-programmed reduction characterization, Cu doping significantly enhanced the performance of the Cu0.3Mn2.7O4 catalyst during low-temperature redox. Finally, these factors synergistically promoted the degradation of CO over the Cu0.3Mn2.7O4 catalyst. In addition, operando diffuse reflectance Fourier transform infrared spectroscopy results suggested the presence of more terminal-type oxygen, which is essential for the catalytic oxidation of CO on the surface of the Cu0.3Mn2.7O4 catalyst. Moreover, the Cu0.3Mn2.7O4 catalyst also showed excellent resistance to carbonate, and remarkable stability.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Caihong Fang,Xiaomin Jiang,Jinwu Hu,Jiaojiao Song,Na Sun,Deliang Zhang,Long Kuai
Ruthenium nanocrystals with small size and special morphology are of great interest in various catalytic reactions due to their high activities. However, it is still a great challenge to downsize these nanocatalysts to a sub-nano scale (<2 nm). Herein, we reported a synthesis of ultrasmall size and uniform Ru nanoparticles through a rapid one-pot method. The prepared Ru nanocrystal shows a wormlike shape, in which the diameter is as thin as 1.6 ± 0.3 nm and the length is 13.6 ± 4.4 nm. These Ru nanoworms (NWs) are quite steady during the synthetic process even though the reaction time was further prolonged. We also examined their catalytic activity toward CO oxidation by loading Ru NWs on TiO2 to form Ru NWs/TiO2 catalysts. These catalysts exhibit a high activity of 100% CO conversion at 150 °C, which is much lower than the normal Ru NPs/TiO2 nanostructures. Based on our detailed investigations, we proposed that the small size, special morphology, and TiO2 support are the keys for their significantly improved catalytic activity. We believed that these reasonable discoveries provide a methodology and opportunity to get highly active catalysts for CO oxidation by a detailed increase in their active sites.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2016
·Vol. 22
·期 46
·16613-16620
·
IF 5.771
Pengyuan Wang,Jia Liu,Chuanfang Liu,Bin Zheng,Xiaoqin Zou,Mingjun Jia,Guangshan Zhu
Graphical Clusters in voids : Very small metal clusters (Au, Pd, Pt) with sizes around 1.2 nm can be facilely encapsulated within sub-nano-sized cavities of zeolitic imidazolate framework 8 (ZIF-8) through electrochemical synthesis. The confined clusters possess clean surfaces and excellent stabilities, as well as superior catalytic properties in CO oxidation including high turnover rates and good selectivity toward reactants based on narrow pore windows (see figure). It is very interesting and also a big challenge to encapsulate metal clusters within microporous solids to expand their application diversity. For this target, herein, we present an electrochemical synthesis strategy for the encapsulation of noble metals (Au, Pd, Pt) within ZIF-8 cavities. In this method, metal precursors of AuCl 4 2− , PtCl 6 2− , and PdCl 4 2− are introduced into ZIF-8 crystals during the concurrent crystallization of ZIF-8 at the anode. As a consequence, very small metal clusters with sizes around 1.2 nm are obtained within ZIF-8 crystals after hydrogen reduction; these clusters exhibit high thermal stability, as evident from the good maintenance of their original sizes after a high-temperature test. The catalytic properties of the encapsulated metal clusters within ZIF-8 are evaluated for CO oxidations. Because of the small pore window of ZIF-8 (0.34 nm) and the confinement effect of small pores, about 80 % of the metal clusters (fractions of 0.74, 0.77, and 0.75 for Au, Pt, and Pd in ZIF-8, respectively) retain their catalytic activity after exposure to the organosulfur poison thiophene (0.46 nm), which is in contrast to their counterparts (fractions of 0.22, 0.25, and 0.20 for Au, Pt, and Pd on the SiO 2 support). The excellent performances of metal clusters encapsulated within ZIF-8 crystals give new opportunities for catalytic reactions.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2014
·Vol. 7
·期 12
·8105-8130
·
IF 1.879
Xiaoshuang Qian,Hongmei Qin,Tao Meng,Yi Lin,Zhen Ma
Oxides (such as SiO2, TiO2, ZrO2, Al2O3, Fe2O3, CeO2) have often been used to prepare supported Pt catalysts for CO oxidation and other reactions, whereas metal phosphate-supported Pt catalysts for CO oxidation were rarely reported. Metal phosphates are a family of metal salts with high thermal stability and acid-base properties. Hydroxyapatite (Ca10(PO4)6(OH)2, denoted as Ca-P-O here) also has rich hydroxyls. Here we report a series of metal phosphate-supported Pt (Pt/M-P-O, M = Mg, Al, Ca, Fe, Co, Zn, La) catalysts for CO oxidation. Pt/Ca-P-O shows the highest activity. Relevant characterization was conducted using N2adsorption-desorption, inductively coupled plasma (ICP) atomic emission spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), CO2temperature-programmed desorption (CO2-TPD), X-ray photoelectron spectroscopy (XPS), and H2temperature-programmed reduction (H2-TPR). This work furnishes a new catalyst system for CO oxidation and other possible reactions.Keywords:metal phosphate;hydroxyapatite;Pt catalyst;CO oxidation
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 60
·37596-37603
·
IF 3.108
Dan Zhao,Chang-Man Tu,Xue-Jing Hu,Ning Zhang
Cu2O is an important compound for many promising applications; however, its real state under serious application conditions, such as redox atmosphere of catalysis reactions, has seldom been investigated. In this study, a dramatic and sustainable activity enhancement for CO oxidation on catalytically used Cu2O nanoporous sphere samples was discovered as compared to that on their fresh counterparts. To illustrate the phenomenon, comprehensive characterizations such as XRD, H2-TPR, TEM, XPS, and CO-TPD were performed on fresh and used Cu2O samples. It was found that after one or several catalytic runs, the main phase among the used samples retained the crystalline feature of Cu2O. However, the surface would transform into a stable multivalent composite interface with almost unchanged Cu(II) : Cu(I) ratio (around 4.0) and active oxygen distribution, even after only one catalytic run for CO oxidation; this indicated a notable reaction-induced or in situ surface restructuring effect of the Cu2O substrates. Compared to that of pure Cu2O, CuO, and reported CuxO samples, the active chemisorbed oxygen on these in situ restructured samples was observed in particularly higher surface composition (with the ratio of chemisorbed oxygen to lattice oxygen being around 5.5); this was further demonstrated to be highly efficient for the oxidization of CO in a relatively low temperature range even in the absence of O2 in the atmosphere and could be the main contributor to speed up CO oxidation in these samples. A similar enhancement in the activity on the used samples for CO oxidation as compared to that on the fresh samples was further testified in Cu2O nanomaterials with different morphologies such as cubic, octahedral, and 18-facet polyhedral nanoparticles; this implied that the surface restructuring effect under a redox reaction atmosphere was a common feature of the Cu2O-based materials, and the transformed surface could act as a superior and stable interface for heterogeneous catalysis. These findings might help in recognizing the real state of Cu2O-containing materials under serious application conditions or designing highly efficient Cu2O-based materials via convenient atmosphere-controlled manipulation for advanced applications.
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
CATALYSIS COMMUNICATIONS
·
2017
·
IF 3.33
Baohuai Zhao,Zesheng Yang,Rui Ran,Zeliang Guo,Xiaodong Wu,Duan Weng
In this work, hollow-structured MnO x and FeO x -MnO x were synthesized by self-template route and applied for CO oxidation . FeO x -MnO x exhibited better catalytic activity than MnO x . It could convert 79.1% CO at 20 °C and had a higher CO conversion during the temperature ramping. The FeO x species could react with HCl and greatly helped to increase the specific surface area (428.5 m 2 g − 1 ) and pore volume (0.82 cm 3 g − 1 ) of the catalyst. The reserved FeO x in the FeO x -MnO x sample enhanced the redox properties and increased the amount of reactive oxygen species.
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
CATALYSIS COMMUNICATIONS
·
2022
·
IF 3.51
Baohuai Zhao,Baofang Jin,Xiaodong Wu,Duan Weng,Rui Ran
A series of Sm-Mn oxides (SmMnO 3 , SmMn 2 O 5 and Sm 0.9 Ag 0.1 Mn 2 O 5 ) of perovskite-type and mullite crystal phases were synthesized for the catalytic oxidation of CO and C 3 H 8 . The Sm 0.9 Ag 0.1 Mn 2 O 5 composition showed the highest catalytic activity among the series of solids, especially for the CO oxidation to CO 2 with T 50 and T 90 values of 60 and 95 °C, respectively. The catalysts were characterized by powder XRD, Raman, BET, XPS, and H 2 -TPR. It was found that the catalytic performance of the solids was correlated well with their redox properties. Synergetic effects between Ag-related species and the mullite phase resulted in more active surface oxygen species and remarkably lowered the reduction temperature of the Sm 0.9 Ag 0.1 Mn 2 O 5 solid.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Liuxin Xu,Ya Pan,Hongmei Li,Ruichao Xu,Zhihu Sun
The presence of interfacial sites between Pt-group metals and transition metal oxides can effectively improve the catalytic activity of Pt-group catalysts, but under moisture-rich conditions they suffer from severe deactivation due to water poisoning of the active sites. Here, we propose for the first time a Lanthanum (La)-doping strategy to improve the water-resistance of the Pt-based catalysts. We synthesized a Pt-CoO/Al 2 O 3 catalyst that is active for CO oxidation under dry conditions but deactivates rapidly under moisture. This rapid deactivation is overcome by La-doping, which delivers boosted activity (100 % CO conversion at 15 °C) and long-term on-stream stability. In situ X-ray absorption fine-structure and in situ diffuse reflectance infrared Fourier transform spectra revealed that the doped La, in the form of La 2 O 3 , plays dual roles of suppressing the carbonate formation on the active sites and modifying the electronic structure of Pt. The synergetic effects between La 2 O 3 and the active Pt−O−Co interfacial sites in La-doped Pt-CoO/Al 2 O 3 lead to the outstanding activity under the moisture-rich condition.
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
MOLECULES
·
2025
·Vol. 30
·期 16
·3388
·
IF 4.6
Shefeng Li,Pengyi Zhao,Ziyang Liu,Chang Wang,Linling Wang,Siyu Ding
Microwave-assisted processing has shown tremendous promise in accelerating chemical reactions and reducing energy consumption through targeted dielectric heating. This study develops MOF-derived Mn-Co and Ce-Co oxide catalysts for energy-efficient benzene oxidation via microwave catalysis. The MnCo spinel oxides (particularly MnCo11-400) exhibit superior microwave absorption and catalytic activity due to enhanced oxygen mobility and tailored dielectric properties. Microwave irradiation enables rapid benzene mineralization over the MnCo11-400 catalyst, achieving 78% conversion at 30 W and complete conversion at 50 W, demonstrating exceptional energy efficiency at low power inputs. Microwaves significantly lower the reaction temperature compared to conventional thermal catalysis (ΔT = 100–250 °C). Stability tests confirm robustness over repeated power cycling (80% conversion retained after 3 × 1 h on/off cycles). Furthermore, an adsorption–microwave oxidation synergistic strategy is demonstrated: pre-adsorbed low-concentration benzene (1.15 mmol) at ambient temperature undergoes complete mineralization within 20 min under 30 W microwave irradiation. The intermittent microwave operation achieves equivalent benzene removal to continuous thermal processing while significantly reducing energy demand. This work establishes MOF-derived spinel oxides as high-performance microwave catalysts for low-temperature VOC abatement.
研究领域:
催化
·
环境化学
·
材料科学
·
微波化学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Siwen Gong,Gangqiang Zhu,Xiaoqian Xie,Fei Rao,Lujun Zhu,Yurong An,Xianjin Shi,Yu Huang,Peng Liu,Mirabbos Hojamberdiev
A novel interface of MnO 2 with CuO with multivalent conversion is fabricated by the deposition-precipitation method for low-temperature and efficient CO oxidation. It is found that the temperature for CO thermal-catalytic oxidation to reach a complete conversion significantly decreases to 105 °C for the CuO/MnO 2 . A combination of experimental and theoretical studies demonstrates the successful formation of the CuO/MnO 2 interface, inducing a pronounced effect that promotes CO oxidation. The CuO/MnO 2 interface leads to the formation of Cu-O-Mn, a superior redox system with multivalent conversion (Cu + + Mn 4+ ↔ Cu 2+ + Mn 3+ , Cu + + Mn 3+ ↔ Cu 2+ + Mn 2+ ), abundant active sites, excellent ability to activate O 2 , the rapid oxygen transfer, and more suitable adsorption energy for O 2 , CO, and CO 2 . These characteristics are advantageous to Cu x O-Mn x O y for achieving a 100 % removal of CO at a lower temperature. Furthermore, the computational study reveals that the CO oxidation process follows two mechanistic pathways (Eley-Rideal (E-R) and Mars-van Krevelen (M-K)), indicating that there is no competitive adsorption of CO and O 2 on the CuO/MnO 2 . This study shows that the interface created between suitable metal oxides can improve the catalytic performance and provides new perspective for catalyst design and performance enhancement mechanisms.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）