Ce0.67Zr0.33O2-Al2O3 solid solution was prepared by the co-precipitation method. Fe2O3-based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal lo...Ce0.67Zr0.33O2-Al2O3 solid solution was prepared by the co-precipitation method. Fe2O3-based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal loading amount of Fe2O3 on Ce0.67Zr0.33 O2-Al2O3 in our experimental condition for catalytic combustion of methane was 8% （ mass fraction）. The prepared catalysts were characterized by BET, TPR, XRD analyses, and their catalytic activity was investigated after being calcined at 873 K and after being aged in water gas at 1273 K. When the loading amount of Fe203 was 8% （ mass fraction）, the catalyst held the highest activity, and the best temperature speciality and thermal stability. The complete-conversion temperature of methane for fresh and aged sample was 788 and 838 K, respectively. The range between the light-off temperature and the complete-conversion temperature was only 15 K. The characterization results of XRD indicated that Fe2O3 was well dispersed on the Ce0.67Zr0.33O2-Al2O3 matrix. The results of BET and TPR were in good harmony with the catalytic activity results.展开更多
Highly dispersed perovskite NdCoO3 nanoparticles were prepared by a novel salt-assisted combustion process. The effects of NaCl content and calcination temperature on the characteristics of the products were character...Highly dispersed perovskite NdCoO3 nanoparticles were prepared by a novel salt-assisted combustion process. The effects of NaCl content and calcination temperature on the characteristics of the products were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET surface area measurement. The facile introduction of NaCl in the conventional combustion synthesis process was found to result in the formation of well-dispersed perovskite nanoparticles and increase specific surface areas of the resultants from 1.7 to 43.2 m2·g-1. The catalytic properties of the typical NdCoO3 samples for thermal decomposition of ammonia perchlorate (AP) and their correlation with the NdCoO3 microstructure were investigated by Differential Scanning Calorimetry (DSC). The DSC results indicate that the addition of the amorphous NdCoO3 nanoparticles to AP incorporates two small exothermic peaks of AP into a strong exothermic peak, decreases the temperature of the AP exothermic peak to 314.0 ℃ by reduction of 138.3 ℃ and increases the apparent decomposition heat from 515 J·g-1 to over 1441 J·g-1, showing the intense catalytic activity for thermal decomposition of AP. It is also clear that the catalytic activity of the resultant NdCoO3 is related to their microstructure. According to Kissinger′s method, the kinetics parameters of the thermal decomposition of AP catalyzed by the as-prepared NdCoO3 samples were calculated to account for the order of their catalytic activity.展开更多
ZrO 2-Al 2O 3 composite oxides and supported Ni catalysts were prepared, and characterized by N 2 adsorption /desorption, X-ray diffraction(XRD) an d X-ray photoelectron spectroscopy(XPS) techniques. The catalytic...ZrO 2-Al 2O 3 composite oxides and supported Ni catalysts were prepared, and characterized by N 2 adsorption /desorption, X-ray diffraction(XRD) an d X-ray photoelectron spectroscopy(XPS) techniques. The catalytic performance and carbon deposition was also investigated. This mesoporous composite oxide is shown to be a promising catalyst support. An increase in the catalytic activity and stability of methane and carbon dioxide reforming reaction was resulted from the zirconia addition, especially at 5wt% ZrO 2 content. The Ni catalyst supported ZrO 2-Al 2O 3 has a strong resistance to sintering and the carbon deposition in a relatively long-term reaction.展开更多
A new Co（Ⅱ） metal-organic coordination polymer based on flexible bis（imidazole） and aromatic dicarboxylate co-ligands, namely [Co（bix）（nph）]n （H2nph = 3-nitrophthalic acid, bix = 1,4-bis（imidazole-l-ylmethy...A new Co（Ⅱ） metal-organic coordination polymer based on flexible bis（imidazole） and aromatic dicarboxylate co-ligands, namely [Co（bix）（nph）]n （H2nph = 3-nitrophthalic acid, bix = 1,4-bis（imidazole-l-ylmethyl）benzene）, has been hydrothermally synthesized and characterized by elemental analyses, TG, IR spectroscopy and single-crystal X-ray diffraction. It crystallizes in the triclinic space group Piwith a = 9.3767（14）, b = 10.1451（15）, c = 12.1488（17） A, α = 102.6450（10）, β = 108.856（2）, ）, = 98.807（2）°, V= 1035.3（3） A3, Z = 2, C22H17CoN5O6, Mr = 506.34, Dc = 1.624 g/cm^3, p = 0.882 mm^-1 and F（000） = 518. In the complex, the nph^2- ligands connect neighbouring cobalt atoms to form binuclear [Co（nph）]2 subunits, which are linked by pairs of bix ligands to form a 2D honeycomb-like （6,3） network. In addition, the compound is further extended into a 3D supramolecular architecture by π…π stacking interactions. Moreover, the luminescence and catalytic properties of the complex are investigated.展开更多
Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been construc...Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been constructed hydrothermally using H_(2)cpna(5-(4-carboxyphenoxy)nicotinic acid),dpea(1,2-di(4-pyridyl)ethane),dpey(1,2-di(4-pyridyl)ethylene),and zinc,cobalt,and nickel chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the triclinic system,space group P1.Compounds 1-3 show 2D layer structures.The catalytic activities in the Knoevenagel condensation reaction of these compounds were investigated.Compounds 1 and 2 exhibit effective catalytic activities in the Knoevenagel condensa-tion reaction at room temperature.For this reaction,various parameters were optimized,followed by the investiga-tion of the substrate scope.CCDC:2335676,1;2335677,2;2335678,3.展开更多
Studies on the synthesis and design of coordination polymers(CPs) with flexible ligands are of great interest owing to their dynamic structures and promising applications. The title coordination polymers, {[Cd·(H...Studies on the synthesis and design of coordination polymers(CPs) with flexible ligands are of great interest owing to their dynamic structures and promising applications. The title coordination polymers, {[Cd·(HTTTA)·(phen)]·2HO}n(1) and [Cd·(HTTTA)·(phen)]n(2)(H3 TTTA = 2,2’,2’’-[1,3,5-triazine-2,4,6-triyltris(thio)] tris-acetic acid, phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, IR, powder XRD and single-crystal X-ray diffraction. Complex 1 consists of one CdII ion, one HTTTA2-ligand and one phen co-ligand. The Cd(Ⅱ) metal clusters were bridged by the tridentate HTTTA2-ligands into infinite 1D chains, which are further connected into the 3D architecture by abundant hydrogen bonds. In 2, three carboxyl groups of HTTTA2-ligand show different coordination directions because of the C–S–C flexible bond angle, which leads to different 1D chains of 2. The strong π-π stacking interaction and four C–H···O hydrogen bonds connect the 1D chains into a 3D framework. The solid-state photoluminescence and catalytic properties were studied as well.展开更多
The crystal structure of meso-tetrakis （4-hydroxyphenyl） porphyrinato manganese chloride （MnTHPPC1） and its supramolecular architecture based on the hydrogen bonds of one counter C1 anion with four hydrogen atoms ...The crystal structure of meso-tetrakis （4-hydroxyphenyl） porphyrinato manganese chloride （MnTHPPC1） and its supramolecular architecture based on the hydrogen bonds of one counter C1 anion with four hydrogen atoms of four-OH groups from different MnTHPPC1 molecules cooperated by self-assembly of the porphyrin units were first repor-ted. This compound crystallized in the tetragonal space group 14/m with a = 1.39928（7） nm, b = 1.39928（7） nm, c =0.94498（10） nm, V= 1.8503（2） nm^3, and Z =2. As a catalyst, MnTHPPC1 also showed a high catalytic acti-vity in the conversion from 1-naphthylamine （1-NA） to his （4-oxo-benzo-2-cyclohexen-l-yl） amine （BOBCHA） v/a oxidative coupling under mild conditions.展开更多
A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The...A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c with a = 9.4760(3), b = 24.0408(8), c = 16.5871(5) A, β = 99.832(3)°, V = 3723.2(2) A3, Z = 4, Dc = 1.348 g/cm3, F(000) = 1576, the final R = 0.0486 and w R = 0.0936 for 2938 observed reflections with I 】 2σ(I) for the complex. Structural analysis shows that the coordination polymer possesses a 2D(4,4) layer structure which is composed of Ni(II) centers bridged by L ligand with two kinds of conformations and further assembled into a 3D supramolecular network via π-π stacking interactions. In addition, the fluorescence and catalytic properties, for the degradation of Congo red, of the complex were investigated.展开更多
β-Co（OH）2 and Mg（OH）2 nanoplates were synthesized via a facile template-free hydrothermal approach.The different conditions of preparation and catalytic properties of the products were studied and discussed.The p...β-Co（OH）2 and Mg（OH）2 nanoplates were synthesized via a facile template-free hydrothermal approach.The different conditions of preparation and catalytic properties of the products were studied and discussed.The products were characterized by X-ray diffraction,transmission electron microscopy,scanning electron microscopy,selected area electron diffraction（SAED）,and gas chromatograph.展开更多
Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been construc...Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3.展开更多
Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(...Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid),phen(1,10-phenanthroline),bpb(1,4-bis(pyrid-4-yl)benzene),bpa(bis(4-pyridyl)amine),and copper,nickel and cadmium chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and singlecrystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three complexes crystallize in the monoclinic P21/n,tetragonal I42d,and orthorhombic P21212 space groups.The complexes exhibit molecular dimers(1)or 2D metal-organic networks(2 and 3).The catalytic performances in the Knoevenagel reaction of these complexes were investigated.Complex 1 exhibits an effective catalytic activity and excellent reusability as a heterogeneous catalyst in the Knoevenagel reaction at room temperature.CCDC:2463800,1;2463801,2;2463802,3.展开更多
The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreas...The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreased leaf relative water content （RWC） and, as a result of drought-induced oxidative stress, the activities of antioxidant enzymes increased significantly. More interestingly, the intensity of applied water stress was correlated with increased production of H2O2 and O2^- and elevated activity of PM NADPH oxidase, a key enzyme of reactive oxygen species generation in plants. Histochemical analyses also revealed increased H2O2 and O2^- production in drought-stressed leaves. Application of diphenylene iodonium （DPI）, an inhibitor of PM NADPH oxidase, did not alleviate drought-induced production of H2O2 and O2^-. Catalysis experiments indicated that the rice PM NADPH oxidase was partially fiavin-dependent. The pH and temperature optima for this enzyme were 9.8 and 40 ℃, respectively. In addition, drought stress enhanced the activity under alkaline pH and high temperature conditions. These results suggest that a complex regulatory mechanism, associated with the NADPH oxidase-H2O2 system, is involved in the response of rice to drought stress.展开更多
In this work, we demonstrated a simple and efficacious two-step method for the synthesis of Ag@Au core–shell nanoparticles(Ag@Au NPs) and the Ag/Au hollow nanocages(Ag/Au NCs) with Ag nanoparticles(Ag NPs) as seeds b...In this work, we demonstrated a simple and efficacious two-step method for the synthesis of Ag@Au core–shell nanoparticles(Ag@Au NPs) and the Ag/Au hollow nanocages(Ag/Au NCs) with Ag nanoparticles(Ag NPs) as seeds by adjusting p H, and the preparation of hybrid Ag@Au NPs- or Ag/Au NCs-graphene oxide nanocomposites(Ag@Au NPs-GO or Ag/Au NCs-GO)based on the self-assembly. It was noticed from the electrostatic assembly experiment that the loading amount of Ag/Au NCs on GO nanosheet was more than that of Ag@Au NPs. The as-synthesized hybrid materials were characterized by transmission electron microscopy, atomic force microscopy, f-potential, high-angle annular darkfield scanning transmission electron microscopy, thermogravimetric analyzer and X-ray diffraction. Catalytic activities of Ag@Au NPs, Ag/Au NCs and Ag/Au NCs-GO nanostructures were investigated in the reduction of 4-, 3-or 2-nitrophenol to 4-, 3- or 2-aminophenol, and on the basis of comparative kinetic studies the following trend was obtained for the related catalytic activity: Ag/Au NCsGO [ Ag/Au NCs [ Ag@Au NPs. These observations were attributed to the simultaneous effects of surface area available for catalytic reaction and composition of the hybrid nanostructures.展开更多
Two coordination polymers,namely[Mn(μ-Hcpia)(bipy)(H_(2)O)_(2)]_(n)(1)and[Cd_(3)(μ3-Hcpia)_(2)(μ-Hbiim)_(2)(μ-H_(2)biim)(H_(2)O)_(2)]n(2),have been constructed hydrothermally using H_(2)cbia(H_(2)cbia=5-(4΄-cyano-...Two coordination polymers,namely[Mn(μ-Hcpia)(bipy)(H_(2)O)_(2)]_(n)(1)and[Cd_(3)(μ3-Hcpia)_(2)(μ-Hbiim)_(2)(μ-H_(2)biim)(H_(2)O)_(2)]n(2),have been constructed hydrothermally using H_(2)cbia(H_(2)cbia=5-(4΄-cyano-benzoxy)isophthalic acid),bipy(bipy=4,4΄-bipyridine),H_(2)biim(H_(2)biim=2,2΄-biimidazole),and manganese or cadmium chlorides at 160℃.Interestingly,the H3cpia(H3cpia=5-(4΄-carboxylphenoxy)isophthalic acid)ligand was generated by in situ hydrolysis of cyano group in H_(2)cbia.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses(TGA),and single-crystal X-ray diffraction analyses.Both compounds crystallize in the triclinic system,space group P1.Compound 1 discloses a 1D linear chain of the 2C1 topological type.Adjacent chains are assembled into a 2D supramolecular sheet through O–H∙∙∙O/N hydrogen bonds.Compound 2 features a 3D framework with a 3,4,4T25 topology.The luminescent and catalytic properties of two compounds were investigated.Compound 1 exhibits a superior catalytic activity in the cyanosilylation at room temperature.展开更多
Surface chemical properties of typical commercial coal-based activated cokes were characterized by Xray photoelectron spectroscopy(XPS) and acid-base titration, and then the influence of surface chemical properties on...Surface chemical properties of typical commercial coal-based activated cokes were characterized by Xray photoelectron spectroscopy(XPS) and acid-base titration, and then the influence of surface chemical properties on catalytic performance of activated cokes of NO reduction with NH3 was investigated in a fixed-bed quartz micro reactor at 150 ℃. The results indicate that the selective catalytic reduction(SCR) activity of activated cokes with the increase of its surface acidic sites and oxygen content,obviously, a correlation between catalytic activity and surface acidic sites content by titration has higher linearity than catalytic activity and surface oxygen content by XPS. While basic sites content by acid-base titration have not correlation with SCR activity. It has been proposed that surface basic sites content measured by titration may not be on adjacent of acidic surface oxides and then cannot form of NO2-like species, thus the reaction of reduction of NO with NH3 have been retarded.展开更多
The effects of cerium substitution,use of additives,and heating temperature on the chemical composition and catalytic activity of iron phosphate were evaluated.Iron-cerium phosphate was prepared from iron nitrate,ammo...The effects of cerium substitution,use of additives,and heating temperature on the chemical composition and catalytic activity of iron phosphate were evaluated.Iron-cerium phosphate was prepared from iron nitrate,ammonium cerium nitrate,and sodium phosphate in ethylene glycol using sodium dodecyl-sulfate or acetylacetone as additive.The chemical composition,particle shape and size distribution of the obtained samples were respectively evaluated based on ICP and XRD,SEM,and laser diffraction/scattering analysis.The catalytic activity was evaluated based on the decomposition of the complex formed from formaldehyde,ammonium acetate,and acetylacetone.XRD peaks corresponding to FePO_(4) were observed for the samples heated at 600℃whereas samples treated at lower temperatures were amorphous.Iron-cerium phosphates heated at 200℃and 400℃exhibited high catalytic activity for the decomposition of the aforementioned complex.展开更多
A silver-based metal-organic framework（Ag-MOFs）, [Ag2（H3 ddcba）（dpp）2]（1）（H5 ddcba = 3,5-（di（2’,5’-dicarboxylphenyl）benozoic acid, dpp = 1,3-di（4-pyridyl）propane）, was successfully constructed via hyd...A silver-based metal-organic framework（Ag-MOFs）, [Ag2（H3 ddcba）（dpp）2]（1）（H5 ddcba = 3,5-（di（2’,5’-dicarboxylphenyl）benozoic acid, dpp = 1,3-di（4-pyridyl）propane）, was successfully constructed via hydrothermal assembly of a pentacaboxylate ligand, a N-donor ligand and Ag（I） ions, which possesses a pcu topology and exhibits excellent catalytic properties in aqueous solution for the degradation of onitrophenol（2-NP）, m-nitrophenol（3-NP） and p-nitrophenol（4-NP）. Related kinetics of such catalytic reactions, photoluminescent and thermal stability of compound 1 were also investigated.展开更多
Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed...Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed hydrothermally using H4adip(H4adip=5,5′-azanediyldiisophthalic acid),phen(phen=1,10-phenanthroline),bipy(bipy=2,2′-bipyridine),bpa(bpa=bis(4-pyridyl)amine),and zinc and cobalt chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffrac-tion analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the orthorhom-bic system Pnna(1 and 2)or P21212(3)space groups.All compounds exhibit 3D frameworks.The catalytic perfor-mances in the Henry reaction of these compounds were investigated.Compound 3 exhibited an effective catalytic activity in the Henry reaction at 70℃.CCDC:2339391,1;2339392,2;2339393,3.展开更多
The functional materials based on natural zeolite （clinoptilolite）, TiO2-zeolite and Ag-TiO2-zeolite have been successfully synthesized by solid-state reaction in fast-hydrothermal conditions. The obtained functiona...The functional materials based on natural zeolite （clinoptilolite）, TiO2-zeolite and Ag-TiO2-zeolite have been successfully synthesized by solid-state reaction in fast-hydrothermal conditions. The obtained functional materials were investigated by X-ray diffraction （XRD）, FT-1R （Fourier transform infrared） spectroscopy, DRUV-VIS （diffuse reflectance ultraviolet-visible） spectroscopy, BET （Brunauer-Emmett-Teller） and SEM/EDX （scanning electron microscope/energy dispersive X-ray spectrometer） analyses. The XRD results indicated that the clinoptilolite structure has a good thermal stabilization after the fast-hydrothermal treatment. Also, the high specific surface area about 92.55 m^2.g^-1 was noticed for Ag-TiO2-zeolite functional material. The presence of dopants was evidenced from EDX spectra. The enhanced bactericidal activity of Ag-TiO2-zeolite catalyst is proved through damaging of Enterococcusfaecalis colonies under visible irradiation, at different material doses and irradiation times.展开更多
Well-crystalline CeO2 nanostructures with the morphology of nanorods and nanocubes were synthesized by a template-free hydro-thermal method. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, Brunaue...Well-crystalline CeO2 nanostructures with the morphology of nanorods and nanocubes were synthesized by a template-free hydro-thermal method. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, Brunauer-Emmett-Teller （BET） nitrogen adsorp-tion-desorption measurements were employed to characterize the synthesized materials. The reducibility and catalytic activity of nanostruc-tured CeO2 were examined by hydrogen temperature-programmed reduction （H2-TPR） and CO oxidation. The results showed that CeO2 nanorods could be converted into CeO2 nanocubes with the increasing of the reaction time and the hydrothermal temperature, CeO2 nanorods became longer gradually with the increasing of the concentrations of NaOH. H2-TPR characterization demonstrated that the intense low-temperature reduction peak in the CeO2 nanorods indicated the amount of hydrogen consumed is larger than CeO2 nanocubes. Meantime the CeO2 nanorods enhanced catalytic activity for CO oxidation, the total conversion temperature was 340 oC. The reasons were that CeO2 nanorods have much smaller crystalline sizes and higher surface areas than CeO2 nanocubes.展开更多
基金Project supported by the National Natural Science Key Foundation of China (20333030)
文摘Ce0.67Zr0.33O2-Al2O3 solid solution was prepared by the co-precipitation method. Fe2O3-based catalysts supported on the solid solution were obtained by the impregnation method. The article revealed that the optimal loading amount of Fe2O3 on Ce0.67Zr0.33 O2-Al2O3 in our experimental condition for catalytic combustion of methane was 8% （ mass fraction）. The prepared catalysts were characterized by BET, TPR, XRD analyses, and their catalytic activity was investigated after being calcined at 873 K and after being aged in water gas at 1273 K. When the loading amount of Fe203 was 8% （ mass fraction）, the catalyst held the highest activity, and the best temperature speciality and thermal stability. The complete-conversion temperature of methane for fresh and aged sample was 788 and 838 K, respectively. The range between the light-off temperature and the complete-conversion temperature was only 15 K. The characterization results of XRD indicated that Fe2O3 was well dispersed on the Ce0.67Zr0.33O2-Al2O3 matrix. The results of BET and TPR were in good harmony with the catalytic activity results.
基金the National Natural Science Foundation of China (50306008)Start up Research Fund of Nanchang University and the Natural Science Foundation of Higher Education Institutions in Anhui Province (KJ2007B231)
文摘Highly dispersed perovskite NdCoO3 nanoparticles were prepared by a novel salt-assisted combustion process. The effects of NaCl content and calcination temperature on the characteristics of the products were characterized by X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET surface area measurement. The facile introduction of NaCl in the conventional combustion synthesis process was found to result in the formation of well-dispersed perovskite nanoparticles and increase specific surface areas of the resultants from 1.7 to 43.2 m2·g-1. The catalytic properties of the typical NdCoO3 samples for thermal decomposition of ammonia perchlorate (AP) and their correlation with the NdCoO3 microstructure were investigated by Differential Scanning Calorimetry (DSC). The DSC results indicate that the addition of the amorphous NdCoO3 nanoparticles to AP incorporates two small exothermic peaks of AP into a strong exothermic peak, decreases the temperature of the AP exothermic peak to 314.0 ℃ by reduction of 138.3 ℃ and increases the apparent decomposition heat from 515 J·g-1 to over 1441 J·g-1, showing the intense catalytic activity for thermal decomposition of AP. It is also clear that the catalytic activity of the resultant NdCoO3 is related to their microstructure. According to Kissinger′s method, the kinetics parameters of the thermal decomposition of AP catalyzed by the as-prepared NdCoO3 samples were calculated to account for the order of their catalytic activity.
文摘ZrO 2-Al 2O 3 composite oxides and supported Ni catalysts were prepared, and characterized by N 2 adsorption /desorption, X-ray diffraction(XRD) an d X-ray photoelectron spectroscopy(XPS) techniques. The catalytic performance and carbon deposition was also investigated. This mesoporous composite oxide is shown to be a promising catalyst support. An increase in the catalytic activity and stability of methane and carbon dioxide reforming reaction was resulted from the zirconia addition, especially at 5wt% ZrO 2 content. The Ni catalyst supported ZrO 2-Al 2O 3 has a strong resistance to sintering and the carbon deposition in a relatively long-term reaction.
基金Project supported by the National Natural Science Foundation of China(No.51474086)
文摘A new Co（Ⅱ） metal-organic coordination polymer based on flexible bis（imidazole） and aromatic dicarboxylate co-ligands, namely [Co（bix）（nph）]n （H2nph = 3-nitrophthalic acid, bix = 1,4-bis（imidazole-l-ylmethyl）benzene）, has been hydrothermally synthesized and characterized by elemental analyses, TG, IR spectroscopy and single-crystal X-ray diffraction. It crystallizes in the triclinic space group Piwith a = 9.3767（14）, b = 10.1451（15）, c = 12.1488（17） A, α = 102.6450（10）, β = 108.856（2）, ）, = 98.807（2）°, V= 1035.3（3） A3, Z = 2, C22H17CoN5O6, Mr = 506.34, Dc = 1.624 g/cm^3, p = 0.882 mm^-1 and F（000） = 518. In the complex, the nph^2- ligands connect neighbouring cobalt atoms to form binuclear [Co（nph）]2 subunits, which are linked by pairs of bix ligands to form a 2D honeycomb-like （6,3） network. In addition, the compound is further extended into a 3D supramolecular architecture by π…π stacking interactions. Moreover, the luminescence and catalytic properties of the complex are investigated.
文摘Three zinc(Ⅱ),cobalt(Ⅱ),and nickel(Ⅱ)coordination polymers,namely[Zn(μ^(3-)cpna)(μ-dpea)_(0.5)]_(n)(1),[Co(μ^(3-)cpna)(μ-dpey)_(0.5)]_(n)(2),and[Ni(μ^(3-)cpna)(μ-dpey)_(0.5)(H_(2)O)]_(n)(3),have been constructed hydrothermally using H_(2)cpna(5-(4-carboxyphenoxy)nicotinic acid),dpea(1,2-di(4-pyridyl)ethane),dpey(1,2-di(4-pyridyl)ethylene),and zinc,cobalt,and nickel chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the triclinic system,space group P1.Compounds 1-3 show 2D layer structures.The catalytic activities in the Knoevenagel condensation reaction of these compounds were investigated.Compounds 1 and 2 exhibit effective catalytic activities in the Knoevenagel condensa-tion reaction at room temperature.For this reaction,various parameters were optimized,followed by the investiga-tion of the substrate scope.CCDC:2335676,1;2335677,2;2335678,3.
基金supported by the National Natural Science Foundation of China(51603086)Natural Science Research in Colleges and Universities in Jiangsu Province(17KJB150037)+2 种基金Science&Technology Development of Jilin Province(20160520131JH)Technology Support Program(Social Development)of Taizhou(TS201628)Undergraduate Training Program for Innovation and Entrepreneurship(201612917021X)
文摘Studies on the synthesis and design of coordination polymers(CPs) with flexible ligands are of great interest owing to their dynamic structures and promising applications. The title coordination polymers, {[Cd·(HTTTA)·(phen)]·2HO}n(1) and [Cd·(HTTTA)·(phen)]n(2)(H3 TTTA = 2,2’,2’’-[1,3,5-triazine-2,4,6-triyltris(thio)] tris-acetic acid, phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, IR, powder XRD and single-crystal X-ray diffraction. Complex 1 consists of one CdII ion, one HTTTA2-ligand and one phen co-ligand. The Cd(Ⅱ) metal clusters were bridged by the tridentate HTTTA2-ligands into infinite 1D chains, which are further connected into the 3D architecture by abundant hydrogen bonds. In 2, three carboxyl groups of HTTTA2-ligand show different coordination directions because of the C–S–C flexible bond angle, which leads to different 1D chains of 2. The strong π-π stacking interaction and four C–H···O hydrogen bonds connect the 1D chains into a 3D framework. The solid-state photoluminescence and catalytic properties were studied as well.
文摘The crystal structure of meso-tetrakis （4-hydroxyphenyl） porphyrinato manganese chloride （MnTHPPC1） and its supramolecular architecture based on the hydrogen bonds of one counter C1 anion with four hydrogen atoms of four-OH groups from different MnTHPPC1 molecules cooperated by self-assembly of the porphyrin units were first repor-ted. This compound crystallized in the tetragonal space group 14/m with a = 1.39928（7） nm, b = 1.39928（7） nm, c =0.94498（10） nm, V= 1.8503（2） nm^3, and Z =2. As a catalyst, MnTHPPC1 also showed a high catalytic acti-vity in the conversion from 1-naphthylamine （1-NA） to his （4-oxo-benzo-2-cyclohexen-l-yl） amine （BOBCHA） v/a oxidative coupling under mild conditions.
基金supported by the Starting Research Fund from Hebei United University(35398599)the Natural Science Foundation of Hebei Province(B2014209182)
文摘A new Ni(II) coordination polymer [Ni(L)2(SCN)2]n(L = 1,4-bis(benzimidazol-1-yl)butane) was synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c with a = 9.4760(3), b = 24.0408(8), c = 16.5871(5) A, β = 99.832(3)°, V = 3723.2(2) A3, Z = 4, Dc = 1.348 g/cm3, F(000) = 1576, the final R = 0.0486 and w R = 0.0936 for 2938 observed reflections with I 】 2σ(I) for the complex. Structural analysis shows that the coordination polymer possesses a 2D(4,4) layer structure which is composed of Ni(II) centers bridged by L ligand with two kinds of conformations and further assembled into a 3D supramolecular network via π-π stacking interactions. In addition, the fluorescence and catalytic properties, for the degradation of Congo red, of the complex were investigated.
基金Supported by the National Natural Science Foundation of China(Nos.20331010,20671011,90406024and90406002)the 111 Project(No.B07012)the Key Laboratory of Structural Chemistry Foundation(No.060017).
文摘β-Co（OH）2 and Mg（OH）2 nanoplates were synthesized via a facile template-free hydrothermal approach.The different conditions of preparation and catalytic properties of the products were studied and discussed.The products were characterized by X-ray diffraction,transmission electron microscopy,scanning electron microscopy,selected area electron diffraction（SAED）,and gas chromatograph.
文摘Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3.
文摘Three copper(Ⅱ),nickel and cadmium(Ⅱ)complexes,namely[Cu_(2)(μ-H2dbda)2(phen)2]·2H_(2)O(1),[Ni(μ-H2dbda)(μ-bpb)(H_(2)O)2]n(2),and[Cd(μ-H2dbda)(μ-bpa)]n(3),have been constructed hydrothermally using H4dbda(4,4'-dihydroxy-[1,1'-biphenyl]-3,3'-dicarboxylic acid),phen(1,10-phenanthroline),bpb(1,4-bis(pyrid-4-yl)benzene),bpa(bis(4-pyridyl)amine),and copper,nickel and cadmium chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and singlecrystal X-ray diffraction analyses.Single-crystal X-ray diffraction analyses revealed that three complexes crystallize in the monoclinic P21/n,tetragonal I42d,and orthorhombic P21212 space groups.The complexes exhibit molecular dimers(1)or 2D metal-organic networks(2 and 3).The catalytic performances in the Knoevenagel reaction of these complexes were investigated.Complex 1 exhibits an effective catalytic activity and excellent reusability as a heterogeneous catalyst in the Knoevenagel reaction at room temperature.CCDC:2463800,1;2463801,2;2463802,3.
基金Supported by the National Natural Science Foundation of China under GrantNo. 30871469the Zhejiang Province Natural Science Foundation of China under Grant No. Y306087
文摘The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreased leaf relative water content （RWC） and, as a result of drought-induced oxidative stress, the activities of antioxidant enzymes increased significantly. More interestingly, the intensity of applied water stress was correlated with increased production of H2O2 and O2^- and elevated activity of PM NADPH oxidase, a key enzyme of reactive oxygen species generation in plants. Histochemical analyses also revealed increased H2O2 and O2^- production in drought-stressed leaves. Application of diphenylene iodonium （DPI）, an inhibitor of PM NADPH oxidase, did not alleviate drought-induced production of H2O2 and O2^-. Catalysis experiments indicated that the rice PM NADPH oxidase was partially fiavin-dependent. The pH and temperature optima for this enzyme were 9.8 and 40 ℃, respectively. In addition, drought stress enhanced the activity under alkaline pH and high temperature conditions. These results suggest that a complex regulatory mechanism, associated with the NADPH oxidase-H2O2 system, is involved in the response of rice to drought stress.
基金supported by the National Natural Science Foundation of China(21105042)the Science Foundation of China Postdoctor(2014M560572)+2 种基金the Natural Science Foundation of Shandong Province(ZR2015BM024)Tai-Shan Scholar Research Fund of Shandong Provincesupported by grant NIH 1R01DA037838 to Drs.Li and Nair
文摘In this work, we demonstrated a simple and efficacious two-step method for the synthesis of Ag@Au core–shell nanoparticles(Ag@Au NPs) and the Ag/Au hollow nanocages(Ag/Au NCs) with Ag nanoparticles(Ag NPs) as seeds by adjusting p H, and the preparation of hybrid Ag@Au NPs- or Ag/Au NCs-graphene oxide nanocomposites(Ag@Au NPs-GO or Ag/Au NCs-GO)based on the self-assembly. It was noticed from the electrostatic assembly experiment that the loading amount of Ag/Au NCs on GO nanosheet was more than that of Ag@Au NPs. The as-synthesized hybrid materials were characterized by transmission electron microscopy, atomic force microscopy, f-potential, high-angle annular darkfield scanning transmission electron microscopy, thermogravimetric analyzer and X-ray diffraction. Catalytic activities of Ag@Au NPs, Ag/Au NCs and Ag/Au NCs-GO nanostructures were investigated in the reduction of 4-, 3-or 2-nitrophenol to 4-, 3- or 2-aminophenol, and on the basis of comparative kinetic studies the following trend was obtained for the related catalytic activity: Ag/Au NCsGO [ Ag/Au NCs [ Ag@Au NPs. These observations were attributed to the simultaneous effects of surface area available for catalytic reaction and composition of the hybrid nanostructures.
基金the Science and Technology Plan of Qinghai Province(2020-ZJ-705)。
文摘Two coordination polymers,namely[Mn(μ-Hcpia)(bipy)(H_(2)O)_(2)]_(n)(1)and[Cd_(3)(μ3-Hcpia)_(2)(μ-Hbiim)_(2)(μ-H_(2)biim)(H_(2)O)_(2)]n(2),have been constructed hydrothermally using H_(2)cbia(H_(2)cbia=5-(4΄-cyano-benzoxy)isophthalic acid),bipy(bipy=4,4΄-bipyridine),H_(2)biim(H_(2)biim=2,2΄-biimidazole),and manganese or cadmium chlorides at 160℃.Interestingly,the H3cpia(H3cpia=5-(4΄-carboxylphenoxy)isophthalic acid)ligand was generated by in situ hydrolysis of cyano group in H_(2)cbia.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses(TGA),and single-crystal X-ray diffraction analyses.Both compounds crystallize in the triclinic system,space group P1.Compound 1 discloses a 1D linear chain of the 2C1 topological type.Adjacent chains are assembled into a 2D supramolecular sheet through O–H∙∙∙O/N hydrogen bonds.Compound 2 features a 3D framework with a 3,4,4T25 topology.The luminescent and catalytic properties of two compounds were investigated.Compound 1 exhibits a superior catalytic activity in the cyanosilylation at room temperature.
基金the High Technology Research and Development Program of China(No.2011AA060803)the Beijing Key Laboratory Annual Program(No.Z121103009212039)
文摘Surface chemical properties of typical commercial coal-based activated cokes were characterized by Xray photoelectron spectroscopy(XPS) and acid-base titration, and then the influence of surface chemical properties on catalytic performance of activated cokes of NO reduction with NH3 was investigated in a fixed-bed quartz micro reactor at 150 ℃. The results indicate that the selective catalytic reduction(SCR) activity of activated cokes with the increase of its surface acidic sites and oxygen content,obviously, a correlation between catalytic activity and surface acidic sites content by titration has higher linearity than catalytic activity and surface oxygen content by XPS. While basic sites content by acid-base titration have not correlation with SCR activity. It has been proposed that surface basic sites content measured by titration may not be on adjacent of acidic surface oxides and then cannot form of NO2-like species, thus the reaction of reduction of NO with NH3 have been retarded.
文摘The effects of cerium substitution,use of additives,and heating temperature on the chemical composition and catalytic activity of iron phosphate were evaluated.Iron-cerium phosphate was prepared from iron nitrate,ammonium cerium nitrate,and sodium phosphate in ethylene glycol using sodium dodecyl-sulfate or acetylacetone as additive.The chemical composition,particle shape and size distribution of the obtained samples were respectively evaluated based on ICP and XRD,SEM,and laser diffraction/scattering analysis.The catalytic activity was evaluated based on the decomposition of the complex formed from formaldehyde,ammonium acetate,and acetylacetone.XRD peaks corresponding to FePO_(4) were observed for the samples heated at 600℃whereas samples treated at lower temperatures were amorphous.Iron-cerium phosphates heated at 200℃and 400℃exhibited high catalytic activity for the decomposition of the aforementioned complex.
基金financial support from the National Science Foundation of China (Nos. 216731272, 2137312, 21671119, 51572152 and 51502155)
文摘A silver-based metal-organic framework（Ag-MOFs）, [Ag2（H3 ddcba）（dpp）2]（1）（H5 ddcba = 3,5-（di（2’,5’-dicarboxylphenyl）benozoic acid, dpp = 1,3-di（4-pyridyl）propane）, was successfully constructed via hydrothermal assembly of a pentacaboxylate ligand, a N-donor ligand and Ag（I） ions, which possesses a pcu topology and exhibits excellent catalytic properties in aqueous solution for the degradation of onitrophenol（2-NP）, m-nitrophenol（3-NP） and p-nitrophenol（4-NP）. Related kinetics of such catalytic reactions, photoluminescent and thermal stability of compound 1 were also investigated.
文摘Three zincand cobaltcoordination polymers,namely{[Zn_(2)(μ_(6)-adip)(phen)_(2)]·4H_(2)O}_(n)(1),{[Co_(2)(μ_(6)-adip)(bipy)_(2)]·4H_(2)O}_(n)(2),and[Co_(2)(μ4-adip)(μ-bpa)_(2)]_(n)(3)have been constructed hydrothermally using H4adip(H4adip=5,5′-azanediyldiisophthalic acid),phen(phen=1,10-phenanthroline),bipy(bipy=2,2′-bipyridine),bpa(bpa=bis(4-pyridyl)amine),and zinc and cobalt chlorides at 160℃.The products were isolated as stable crystalline solids and were characterized by IR spectra,elemental analyses,thermogravimetric analyses,and single-crystal X-ray diffrac-tion analyses.Single-crystal X-ray diffraction analyses revealed that three compounds crystallize in the orthorhom-bic system Pnna(1 and 2)or P21212(3)space groups.All compounds exhibit 3D frameworks.The catalytic perfor-mances in the Henry reaction of these compounds were investigated.Compound 3 exhibited an effective catalytic activity in the Henry reaction at 70℃.CCDC:2339391,1;2339392,2;2339393,3.
基金Supported by the Sectoral Operational Programme Human Resources Development(SOP HRD)Financed from the European Social Fundthe Romanian Government under the Contract Number POSDRU/89/1.5/S/63700
文摘The functional materials based on natural zeolite （clinoptilolite）, TiO2-zeolite and Ag-TiO2-zeolite have been successfully synthesized by solid-state reaction in fast-hydrothermal conditions. The obtained functional materials were investigated by X-ray diffraction （XRD）, FT-1R （Fourier transform infrared） spectroscopy, DRUV-VIS （diffuse reflectance ultraviolet-visible） spectroscopy, BET （Brunauer-Emmett-Teller） and SEM/EDX （scanning electron microscope/energy dispersive X-ray spectrometer） analyses. The XRD results indicated that the clinoptilolite structure has a good thermal stabilization after the fast-hydrothermal treatment. Also, the high specific surface area about 92.55 m^2.g^-1 was noticed for Ag-TiO2-zeolite functional material. The presence of dopants was evidenced from EDX spectra. The enhanced bactericidal activity of Ag-TiO2-zeolite catalyst is proved through damaging of Enterococcusfaecalis colonies under visible irradiation, at different material doses and irradiation times.
基金Project supported by National Natural Science Foundation of China (20603016)the National Key Basic Research and Development Program (973 program,2009CB220010)+1 种基金the Scientific Research Fund of Liaoning Provincial Education Department (L2010222)Liaoning Provincial Science & Technology Project of China (20071074) for financial support of this research
文摘Well-crystalline CeO2 nanostructures with the morphology of nanorods and nanocubes were synthesized by a template-free hydro-thermal method. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, Brunauer-Emmett-Teller （BET） nitrogen adsorp-tion-desorption measurements were employed to characterize the synthesized materials. The reducibility and catalytic activity of nanostruc-tured CeO2 were examined by hydrogen temperature-programmed reduction （H2-TPR） and CO oxidation. The results showed that CeO2 nanorods could be converted into CeO2 nanocubes with the increasing of the reaction time and the hydrothermal temperature, CeO2 nanorods became longer gradually with the increasing of the concentrations of NaOH. H2-TPR characterization demonstrated that the intense low-temperature reduction peak in the CeO2 nanorods indicated the amount of hydrogen consumed is larger than CeO2 nanocubes. Meantime the CeO2 nanorods enhanced catalytic activity for CO oxidation, the total conversion temperature was 340 oC. The reasons were that CeO2 nanorods have much smaller crystalline sizes and higher surface areas than CeO2 nanocubes.
