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| 1 | Flower-, wire-, and sheet-like MnO_2-deposited diatomites:Highly efficient absorbents for the removal of Cr(Ⅵ)显示文摘Flower-, wire-, and sheet-like MnO2-deposited diatomites have been prepared using a hydrothermal method with Mn(Ac)2, KMnO4and/or MnSO4 as Mn source and diatomite as support. Physical properties of the materials were characterized by means of numerous analytical techniques, and their behaviors in the adsorption of chromium(VI) were evaluated.It is shown that the MnO2-deposited diatomite samples with different morphologies possessed high surface areas and abundant surface hydroxyl groups(especially the wire-like MnO2/diatomite sample). The wire-like MnO2/diatomite sample showed the best performance in the removal of Cr(VI), giving the maximum Cr(VI) adsorption capacity of 101 mg/g. | Yucheng Du Liping Wang Jinshu Wang Guangwei Zheng Junshu Wu Hongxing Dai | 2015 | Journal of Environmental Sciences2015,27,3: | 17 |
| 2 | Water-bathing synthesis of high-surface-area zeolite P from diatomite显示文摘Zeolite P was synthesized for the first time via a novel water-bathing route at 90 C using scrubbed diatomite,sodium hydroxide,and aluminum hydroxide as precursor,with SiO 2/Al 2 O 3,SiO 2/Na 2 O,and H 2 O/Na 2 O molar ratios of 7.43,3.81,and 80.00,respectively.The as-fabricated samples were characterized by means of scanning electron microscopy,X-ray diffraction,and nitrogen adsorption measurements.This study showed that (i) treating the diatomite raw material with sodium hexametaphosphate could open the pores in the diatomite via removal of the clay clogged in its pores;(ii) tetragonal mesoporous zeolite P samples with a surface area of 56-60 m 2/g could be generated after 6-24 h of water-bathing reaction at 90 C;(iii) extension of water-bathing reaction time could improve the mesoporous structure of zeolite P;and (iv) Ca 2+ adsorption capacity of the zeolite P sample was about 300 cmol/kg.Such high-surface-area porous zeolite P could be used as an effective adsorbent for the treatment of water containing calcium and magnesium ions. | Yucheng Du Shuli Shi Hongxing Dai | 2011 | Particuology2011,9,2: | 14 |
| 3 | Rare earth oxides and their supported noble metals in application of environmental catalysis显示文摘Volatile organic compounds(VOCs),methane,carbon monoxide,soot,automotive exhaust,and nitrogen oxides are harmful to the atmosphere and human health.It is urgent to strictly control their emissions.Heterogeneous catalysis is an effective pathway for the removal of these pollutants,and the critical issue is the development of novel and high-performance catalysts.In this review,we briefly summarize the preparation methods,physicochemical properties,catalytic activities,and related reaction mechanisms for the above pollutants removal of the rare earth oxides,mixed rare earth oxide,rare earth oxidesupported noble metal,and mixed rare earth oxide-supported noble metal catalysts that have been investigated by our group and other researchers.It was found that catalytic performance was associated with the factors,such as specific surface area,pore structure,particle size and dispersion,adsorbed oxygen species concentration,reducibility,reactant activation ability or interaction between metal nanoparticles and support.Furthermore,we also envision the development trend of such a topic in future work. | Zhiquan Hou Wenbo Pei Xing Zhang Kunfeng Zhang Yuxi Liu Jiguang Deng Lin Jing Hongxing Dai | 2020 | Journal of Rare Earths2020,38,8: | 10 |
| 4 | Concurrent catalytic removal of typical volatile organic compound mixtures over Au-Pd/α-MnO2 nanotubes显示文摘α-MnO_2 nanotubes and their supported Au-Pd alloy nanocatalysts were prepared using hydrothermal and polyvinyl alcohol-protected reduction methods, respectively. Their catalytic activity for the oxidation of toluene/m-xylene, acetone/ethyl acetate, acetone/m-xylene and ethyl acetate/m-xylene mixtures was evaluated. It was found that the interaction between Au-Pd alloy nanoparticles and α-MnO_2 nanotubes significantly improved the reactivity of lattice oxygen, and the 0.91 wt.% Au0.48 Pd/α-MnO_2 nanotube catalyst outperformed the α-MnO_2 nanotube catalyst in the oxidation of toluene, m-xylene, ethyl acetate and acetone. Over the0.91 wt.% Au0.48 Pd/α-MnO_2 nanotube catalyst,(i) toluene oxidation was greatly inhibited in the toluene/m-xylene mixture, while m-xylene oxidation was not influenced;(ii) acetone and ethyl acetate oxidation suffered a minor impact in the acetone/ethyl acetate mixture; and(iii) m-xylene oxidation was enhanced whereas the oxidation of the oxygenated VOCs(volatile organic compounds) was suppressed in the acetone/m-xylene or ethyl acetate/m-xylene mixtures. The competitive adsorption of these typical VOCs on the catalyst surface induced an inhibitive effect on their oxidation, and increasing the temperature favored the oxidation of the VOCs. The mixed VOCs could be completely oxidized into CO_2 and H_2 O below 320°C at a space velocity of 40,000 m L/(g·hr). The 0.91 wt.% Au0.48 Pd/α-MnO_2 nanotube catalyst exhibited high catalytic stability as well as good tolerance to water vapor and CO_2 in the oxidation of the VOC mixtures. Thus, the α-MnO_2 nanotube-supported noble metal alloy catalysts hold promise for the efficient elimination of VOC mixtures. | Yunsheng Xia Lu Xia Yuxi Liu Tao Yang Jiguang Deng Hongxing Dai | 2018 | Journal of Environmental Sciences2018,30,2: | 7 |
| 5 | Hydrothermal fabrication and visible-light-driven photocatalytic properties of bismuth vanadate with multiple morphologies and/or porous structures for Methyl Orange degradation显示文摘Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100°C with poly(vinyl pyrrolidone) (PVP) and urea (pH = 2) and at 160°C with NaHCO3 (pH = 7 and 8), respectively. The PVP-derived BiVO4 showed much higher surface areas (5.0-8.4 m2/g) and narrower bandgap energies (2.45-2.49 eV). The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture. | Haiyan Jiang Hongxing Dai Xue Meng Lei Zhang Jiguang Deng Yuxi Liu Chak Tong Au | 2012 | Journal of Environmental Sciences2012,24,3: | 5 |
| 6 | Fabrication and characterization of Ce_(0.7)Zr_( 0.3)O_2 nanorods having high specific surface area and large oxygen storage capacity显示文摘Nanorod-like Ce 0.7 Zr 0.3 O 2 solid solutions were synthesized by a sodium dodecyl sulfate-assisted precipi- tation method. The samples were characterized by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and specific surface area measurement. Typical Ce 0.7 Zr 0.3 O 2 nanorods were 40 nm in average diameter and 450 nm in length, with specific surface area and oxygen storage capacity of 194 m 2 /g and 374 mol/g, respectively. | Yucheng Du Shuli Shi Hong He Hongxing Dai | 2011 | Particuology2011,9,1: | 5 |
| 7 | Porous FeO_x/BiVO_(4-δ)S_(0.08): Highly efcient photocatalysts for the degradation of Methylene Blue under visible-light illumination显示文摘Porous S-doped bismuth vanadate with an olive-like morphology and its supported iron oxide(y wt.% FeOx/BiVO4 δS0.08, y =0.06, 0.76, and 1.40) photocatalysts were fabricated using the dodecylamine-assisted alcohol-hydrothermal and incipient wetness impregnation methods, respectively. It is shown that the y wt.% FeOx/BiVO4 δS0.08photocatalysts contained a monoclinic scheetlite BiVO4 phase with a porous olive-like morphology, a surface area of 8.8–9.2 m2/g, and a bandgap energy of 2.38–2.42 eV. There was co-presence of surface Bi5+, Bi3+, V5+, V3+, Fe3+, and Fe2+species in y wt.% FeOx/BiVO4 δS0.08. The 1.40 wt.% FeOx/BiVO4 δS0.08sample performed the best for Methylene Blue degradation under visible-light illumination. The photocatalytic mechanism was also discussed. We believe that the sulfur and FeOx co-doping, higher oxygen adspecies concentration, and lower bandgap energy were responsible for the excellent visible-light-driven catalytic activity of 1.40 wt.% FeOx/BiVO4 δS0.08. | Zhenxuan Zhao Hongxing Dai Jiguang Deng Yuxi Liu Yuan Wang Xinwei Li Guangmei Bai Baozu Gao Chak Tong Au | 2013 | Journal of Environmental Sciences2013,25,10: | 4 |
| 8 | Environmental catalysis: a solution for the removal of atmospheric pollutants显示文摘Atmospheric pollutants such as nitrogen oxides(NO x),carbon monoxide,and volatile organic compounds(VOCs),chiefly emanating from industrial activities and transportation vehicles,are harmful to human health.Catalysis is one of the most effective and economic technologies to control serious air pollution problems;however,the key issue is the availability of high-performance catalysts.Great efforts have been made to develop | Hongxing Dai | 2015 | Science Bulletin2015,60,19: | 4 |
| 9 | Synthesis and characterization of wormhole-like mesoporous Ce_(0.6)Zr_(0.35)Y_(0.05)O_2 solid solutions显示文摘Nanoparticles of Ce0.6Zr0.35Y0.05O2 (CZY) solid solution have been prepared by the CTAB (hexadecyl-trimethyl ammonium bromide), CTAB-EG (ethylene glycol) templating, and CTAB-EG-NaCl (in which the pores of the precursor synthesized by the CTAB-EG method is filled by a certain amount of NaCl) method, respectively. The physical properties of these materials were characterized by means of tech-niques such as X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and N2 adsorp-tion-desorption measurements. The CZY samples synthesized by the above three methods display wormhole-like mesoporous morphology and cubic crystal structures. The materials are narrow in pore size distribution (averaged pore diameter = 5.3―7.1 nm), high in surface areas (95―119 m2/g), and large in pore volumes (0.16―0.18 cm3/g). It has been demonstrated that the introduction of NaCl is capable of retaining the pore structures of solid nanomaterials at high-temperature calcination. | WANG GuoZhi ZHANG Lei DENG JiGuang DAI HongXing HE Hong ZI XueHong | 2007 | Chinese Science Bulletin2007,52,2: | 4 |
| 10 | Preparation and catalytic performance of Fe-SBA-15 and FeO_x/SBA-15 for toluene combustion显示文摘High-surface-area and well-ordered mesoporous Fe-incorporated SBA-15(xFe-SBA-15)and SBA-15-supported FeOx(yFeOx/SBA-15)with the Fe surface density between 0.09 to 1.11 Fe-atom/nm2have been prepared using the one-step synthesis and incipient wetness impregnation methods,respectively.Physicochemical properties of these materials were characterized by means of numerous techniques,and their catalytic activities for the combustion of toluene were evaluated.It is found that the xFe-SBA-15 and yFeOx/SBA-15 samples possessed rod-or chain-like morphologies.The Fe species were of high dispersion when the Fe surface density was lower than0.76 Fe-atom/nm2in xFe-SBA-15 and 0.64 Fe-atom/nm2in yFeOx/SBA-15.At a similar Fe surface density and space velocity,the xFe-SBA-15 catalysts showed better activity than the yFeOx/SBA-15 catalysts,in which the xFe-SBA-15 catalyst with Fe surface density 0.59 Fe-atom/nm2performed the best.It is concluded that the good performance of the xFe-SBA-15 sample with Fe surface density0.59 Fe-atom/nm2was associated with its large surface area,high Fe species dispersion,and good low-temperature reducibility. | Yujuan Zhang Jiguang Deng Lei Zhang Hongxing Dai | 2014 | Chinese Science Bulletin2014,59,31: | 4 |
| 11 | Surfactant-aided hydrothermal preparation of La(2-x)Sr_xCuO_4 single crystallites and their catalytic performance on methane combustion显示文摘Perovskite-like oxide La2-xSrxCuO4 (x = 0, 1) single crystallites with microrod-like morphologies and tetragonal crystal structures were prepared hydrothermally at 240°C with poly(ethylene glycol) (PEG) or hexadecyltrimethyl ammonium bromide (CTAB) as a surfactant and after calcination at 850°C. The physicochemical properties of the materials were characterized by means of XRD, BET, SEM, TEM/SAED (selected-area electron diffraction), XPS and H2-TPR techniques. It is found that doping Sr2+ to La2CuO4 lattice enhanced the catalytic activity for methane combustion and the LaSrCuO4 catalyst derived from PEG is the best among the tested ones. It is concluded that factors, such as adsorbed oxygen species concentration, reducibility and surface area, determined the catalytic performance of such single-crystalline materials. | Lei Zhang Yue Zhang Jiguang Deng Hongxing Dai | 2012 | Journal of Natural Gas Chemistry2012,21,1: | 4 |
| 12 | High-temperature phase transition behavior and magnetocaloric effect in a sub-rapidly solidified La–Fe–Si plate produced by centrifugal casting显示文摘A sub-rapidly solidified La Fe_(11.6)Si_(1.4)plate was fabricated directly from liquid by centrifugal casting method.The phase constitution,microstructure and magnetocaloric effect were investigated using backscatter scanning electron microscopy,X-ray diffraction,differential scanning calorimetry and physical property measurement system.When the plate was annealed at 1373 K,1 phase was formed by a solid-state peritectoid reaction.A first-order magnetic phase transition occurred in the vicinity of188 K,and the effective refrigeration capacities reached 203.5 J/kg and 209.7 J/kg in plates annealed for1 h and 3 h,respectively,under a magnetic field change of 3 T.It is suggested that centrifugal casting may become a new approach to prepare high-performance La–Fe–Si magnetocaloric plates for practical applications,which could largely accelerate the formation of 1 phase during high-temperature heat-treatment process due to refined and homogeneous honeycombed microstructure. | Zhishuai Xu Yuting Dai Yue Fang Zhiping Luo Ke Han Changjiang Song Qijie Zhai Hongxing Zheng | 2018 | Journal of Materials Science & Technology2018,34,8: | 4 |
| 13 | Preparation of ceria-zirconia solid solution with enhanced oxygen storage capacity and redox performance显示文摘A new method called ultrasonic-assisted membrane reaction(UAMR)was reported for the fabrication of ceria-zirconia solid solution.A series of ceria-zirconia solid solutions with different Ce/Zr molar ratios were prepared by the UAMR method and characterized by Xray diffraction(XRD),N2 adsorption,hydrogen temperature-programmed reduction(H2-TPR),scanning electron microscope(SEM),and transmission electron microscopy(TEM)techniques.The UAMR method proved to be superior,especially when the Ce/Zr molar ratio was lower than 1,in fabricating ceria-zirconia solid solutions with large BET surface area,high oxygen storage capacity(OSC),and low reduction temperature. | Lijing MENG Licheng LIU Xuehong ZI Hongxing DAI Zhen ZHAO Xinping WANG Hong HE | 2010 | Frontiers of Environmental Science & Engineering2010,4,2: | 3 |
| 14 | Catalytic oxidation of carbon monoxide, toluene, and ethyl acetate over the xPd/OMS-2 catalysts: Effect of Pd loading显示文摘在 cryptomelane 类型锰氧化物上支持的 Pd 催化剂八面的分子的筛(OMS-2 ) 被准备。在 xPd/OMS-2 上在碳一氧化物,甲苯,和乙醇醋酸盐的催化氧化上装载的 Pd 的效果被调查了。结果证明装载的 Pd 在与是的 0.5Pd/OMS-2 催化剂超过 Pd 免费的对应物的 xPd/OMS-2 催化剂的物理化学的性质上起一个重要作用最好。为 50% 变换的温度是 25, 240 和 160 迥龔鳥蚈? 蒚? ?? ? | Zhidan Fu Lisha Liu Yong Song Qing Ye Shuiyuan Cheng Tianfang Kang Hongxing Dai | 2017 | Frontiers of Chemical Science and Engineering2017,11,2: | 3 |
| 15 | Au-Pd/mesoporous Fe_2O_3:Highly active photocatalysts for the visible-light-driven degradation of acetone显示文摘Three-dimensionally ordered mesoporous Fe_2O_3(meso-Fe_2O_3) and its supported Au, Pd,and Au-Pd alloy(xA uP dy/meso-Fe_2O_3; x = 0.08–0.72 wt.%; Pd/Au molar ratio(y) = 1.48–1.85)photocatalysts have been prepared via the KIT-6-templating and polyvinyl alcohol-protected reduction routes, respectively. Physical properties of the samples were characterized, and their photocatalytic activities were evaluated for the photocatalytic oxidation of acetone in the presence of a small amount of H_2O_2 under visible-light illumination. It was found that the meso-Fe_2O_3 was rhombohedral in crystal structure. The as-obtained samples displayed a high surface area of 111.0–140.8 m^2/g and a bandgap energy of 1.98–2.12 eV. The Au, Pd and/or Au–Pd alloy nanoparticles(NPs) with a size of 3–4 nm were uniformly dispersed on the surface of the meso-Fe_2O_3 support. The 0.72 wt.% AuP d1.48/meso-Fe_2O_3 sample performed the best in the presence of 0.06 mol/L H_2O_2 aqueous solution, showing a 100% acetone conversion within4 hr of visible-light illumination. It was concluded that the good performance of 0.72 wt.%AuPd_(1.48)/meso-Fe_2O_3 for photocatalytic acetone oxidation was associated with its ordered mesoporous structure, high adsorbed oxygen species concentration, plasmonic resonance effect between AuPd_(1.48) NPs and meso-Fe_2O_3, and effective separation of the photogenerated charge carriers. In addition, the introduction of H_2O_2 and the involvement of the photo-Fenton process also played important roles in enhancing the photocatalytic activity of 0.72 wt.%AuPd_(1.48)/meso-Fe_2O_3. | Hongxia Lin Yuxi Liu Jiguang Deng Kunfeng Zhang Xing Zhang Shaohua Xie Xingtian Zhao Jun Yang Zhuo Han Hongxing Dai | 2018 | Journal of Environmental Sciences2018,30,8: | 2 |
| 16 | Adsorption performance of CMK-3 and C-FDU-15 in NO removal at low temperature显示文摘CMK-3 and C-FDU-15 samples were synthesized using hard-templating and evaporationinduced self-assembly(EISA)methods,respectively.The pore structures of CMK-3 and CFDU-15 as well as commercial activated carbon were characterized by means of X-ray diffraction,field emission scanning electron microscopy,transmission electron microscopy,and N2 adsorption–desorption.Adsorption of NO was investigated by means of thermogravimetric analysis,temperature-programmed desorption of NO+O2,and in situ diffuse reflectance Fourier transform infrared spectroscopy.The results show that the CMK-3 and C-FDU-15 materials possessed ordered and uniform structures.The coadsorption capacity of NO and O2 decreased in the sequence CMK-3(88.6 mg/g)>C-FDU-15(71.7 mg/g)>AC(25.3 mg/g).There were two main adsorption species on CMK-3 and CFDU-15:nitrite and nitrate.Nitrite is converted to nitrate easily.However,the adsorption species were more complex on AC,with nitrite being the main species.Moreover,CMK-3 and C-FDU-15 exhibit excellent regeneration efficiency compared with AC.The excellent NO adsorption performance of CMK-3 and C-FDU-15 was associated with their ordered mesoporous structures and high surface areas.The research provides more options for NO adsorption in the future. | Runping Wu Qing Ye Kai Wu Shuiyuan Cheng Tianfang Kang Hongxing Dai | 2020 | Journal of Environmental Sciences2020,32,1: | 2 |
| 17 | Graphitic carbon nitride-based photocatalysts in the applications of environmental catalysis显示文摘Semiconductor photocatalytic technology has shown great prospects in converting solar energy into chemical energy to mitigate energy crisis and solve environmental pollution problems.The key issue is the development of high-efficiency photocatalysts.Various strategies in the state-of-the-art advancements,such as heterostructure construction,heteroatom doping,metal/single atom loading,and defect engineering,have been presented for the graphitic carbon nitride(g-C3N4)-based nanocomposite catalysts to design their surface chemical environments and internal electronic structures to make them more suitable for different photocatalytic applications.In this review,nanoarchitecture design,synthesis methods,photochemical properties,potential photocatalytic applications,and related reaction mechanisms of the modified high-efficiency carbon nitride-based photocatalysts were briefly summarized.The superior photocatalytic performance was identified to be associated with the enhanced visible-light response,fast photoinduced electron-hole separation,efficient charge migration,and increased unsaturated active sites.Moreover,the further advance of the visible-light harvesting and solar-to-energy conversions are proposed. | Hongxia Lin JinmoWu Fan Zhou Xiaolong Zhao Pengfei Lu Guanghui Sun Yuhan Song Yayun Li Xiaoyong Liu Hongxing Dai | 2023 | Journal of Environmental Sciences2023,,2: | 2 |
| 18 | Nb_2O_5 nanowires in-situ grown on carbon fiber: A high-efficiency material for the photocatalytic reduction of Cr(Ⅵ)显示文摘Niobium oxide nanowire-deposited carbon fiber(CF) samples were prepared using a hydrothermal method with amorphous Nb_2O_5·nH_2O as precursor. The physical properties of the samples were characterized by means of numerous techniques, including X-ray diffraction(XRD), energy-dispersive spectroscopy(EDS), scanning electron microscopy(SEM), transmission electron microscopy(TEM), selected-area electron diffraction(SAED), UV–visible spectroscopy(UV–vis), N_2 adsorption–desorption, Fourier transform infrared spectroscopy(FT-IR), and X-ray photoelectron spectroscopy. The efficiency for the removal of Cr(VI) was determined.Parameters such as pH value and initial Cr(VI) concentration could influence the Cr(VI) removal efficiency or adsorption capacity of the Nb_2O_5/carbon fiber sample obtained after hydrothermal treatment at 160°C for 14 hr. The maximal Cr(VI) adsorption capacity of the Nb_2O_5 nanowire/CF sample was 115 mg/g. This Nb_2O_5/CF sample also showed excellent photocatalytic activity and stability for the reduction of Cr(VI) under UV-light irradiation: the Cr(VI) removal efficiency reached 99.9% after UV-light irradiation for 1 hr and there was no significant decrease in photocatalytic performance after the use of the sample for 10 repeated cycles. Such excellent Cr(VI) adsorption capacity and photocatalytic performance was related to its high surface area,abundant surface hydroxyl groups, and good UV-light absorption ability. | Yucheng Du Shihao Zhang Jinshu Wang Junshu Wu Hongxing Dai | 2018 | Journal of Environmental Sciences2018,30,4: | 2 |
| 19 | Preparation and characterization of highly active nanosized strontium-doped lanthanum cobaltate catalysts with high surface areas显示文摘La1?xSrxCoO3?δ (x=0, 0.4) nanoparticles have been prepared using the citric acid complex-ing-hydrothermal synthesis coupled method and citric acid complexing method. The physico-chemical properties of these materials were characterized by means of X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), element analysis (EDX), X-ray photoelectron spectroscopic (XPS), oxygen temperature-programmed desorption (O2-TPD), hydrogen temperature-programmed re-duction (H2-TPR) as well as surface area measure-ments and oxidation state titration. Their catalytic performance was examined for the total oxidation of ethylacetate (EA). It is found that the La1?xSrxCoO3?δ (x=0, 0.4) catalysts were single-phase and rhombo-hedrally-structured perovskites and their surface ar-eas ranged from 16 to 26 m2/g. The Sr-doped sample derived from the coupled procedure was uniformly distributed nanoparticles with a short rod-shaped morphology. The doping of Sr (i) enhanced the con-centrations of Co3+ and oxygen vacancies, (ii) in-creased the amount of oxygen adsorbed on the sur-face at low temperatures, (iii) promoted the mobility of lattice oxygen, and (iv) improved the properties of redox. The La0.6Sr0.4CoO2.78 catalyst prepared by the citric acid complexing-hydrothermal synthesis cou-pled strategy performed the best in the oxidation of EA, furthermore no partially oxidized products were formed. Based on the above results, we conclude that in addition to the surface area, the catalytic ac-tivity of the perovskite-type oxide nanoparticles was associated with the structural defect (oxygen vacancy) concentration and redox ability. | NIU Jianrong LIU Wei DAI Hongxing HE Hong Zl Xuehong LI Peiheng | 2006 | Chinese Science Bulletin2006,51,14: | 2 |
| 20 | A comparative investigation of NdSrCu_(1-x) Co_x O_(4-δ) and Sm_(1.8) Ce_(0.2) Cu_(1-x) Co_x O_(4-δ) (x:0–0.4) for NO decomposition显示文摘A series of single-phase T-structured NdSrCu 1-x Co x O 4-δ with oxygen vacancies and T -structured Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ (x: 0–0.4) with oxygen excess were prepared using ultrasound-assisted citric acid complexing method, and characterized by means of techniques such as thermogravimetric analysis and NO temperature-programmed desorption (NO-TPD). The catalytic activities of these materials were evaluated for the decomposition of NO. It was found that the NdSrCu 1-x Co x O 4-δ catalysts were of oxygen vacancies whereas the Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ ones possessed excessive oxygen (i.e., over-stoichiometric oxygen); with a rise in Co doping level, the oxygen vacancy density of NdSrCu 1-x Co x O 4-δ decreased while the over-stoichiometric oxygen amount of Sm 1.8 Ce 0.2 Cu 1-x Co x O 4-δ increased. The NO-TPD results revealed that NO could be activated much easier over the oxygen-deficient perovskite-like oxides than over the oxygen-excessive perovskite-like oxides, with the NdSrCuO 3.702 catalyst showing the best efficiency in activating NO molecules. Under the conditions of 1.0% NO/helium, 2800 hr -1 , and 600–900°C, the catalytic activity of NO decomposition followed the order of NdSrCuO 3.702 > NdSrCu 0.8 Co 0.2 O 3.736 > NdSrCu 0.6 Co 0.4 O 3.789 > Sm 1.8 Ce 0.2 Cu 0.6 Co 0.4 O 4.187 > Sm 1.8 Ce 0.2 Cu 0.8 Co 0.2 O 4.104 > Sm 1.8 Ce 0.2 CuO 4.045 , in concord with the sequence of decreasing oxygen vacancy or oxygen excess density. Based on the results, we concluded that the higher oxygen vacancy density and the stronger Cu 3+ /Cu 2+ redox ability of NdSrCu 1-x Co x O 4-δ account for the easier activation of NO and consequently improve the catalytic activity of NO decomposition over the catalysts. | Jiguang Deng Lei Zhang Yunsheng Xia Hongxing Dai Hong He | 2010 | Journal of Environmental Sciences2010,22,3: | 2 |