Significant scientific and economic benefits may be derived from investigating the best choice of catalyst in the alkyd resin synthesis. The effect of catalyst type and concentration on the production of alkyd resin u...Significant scientific and economic benefits may be derived from investigating the best choice of catalyst in the alkyd resin synthesis. The effect of catalyst type and concentration on the production of alkyd resin using castor seed oil (CSO) was evaluated. Lithium hydroxide, lead (II) oxide, calcium carbonate, sodium hydroxide and calcium oxide were investigated. The fatty acid profile of the raw CSO was determined using GC-MS while structural elucidation of the CSO based alkyd resins was determined using FTIR spectrometry. The CSO modified alkyd resin produced has acid values of 5.0, 5.61, 7.0 8.24 and 11 for lithium hydroxide, lead (II) oxide, calcium carbonate, sodium hydroxide and calcium oxide respectively. The extent of reaction was 95%, 95%, 91%, 89% and 88% for lithium hydroxide, lead (II) oxide, calcium carbonate, sodium hydroxide and calcium oxide respectively at the reaction time of 150 minutes. The alcoholysis reaction completion time was fastest in LiOH followed by PbO, CaCO<sub>3</sub>, NaOH and CaO catalyst. Physico-chemical parameters of the oil and performance evaluation of the alkyd films suggest that they are sustainable materials for surface coating. LiOH shows excellent robustness to expanded process parameters.展开更多
A series of perovskite type oxides and supported Ag catalysts were prepared, and characterized by X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS). The catalytic activities of the catalyst...A series of perovskite type oxides and supported Ag catalysts were prepared, and characterized by X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS). The catalytic activities of the catalysts as well as influencing factors on catalytic activity have been investigated for the simultaneous removal of NOx and diesel soot particulate. An increase in catalytic activity for the selective reduction of NOx was observed with Ag addition in these perovskite oxides, especially with 5% Ag loading. This catalyst could be a promising candidate of catalytic material for the simultaneous elimination of NOx and diesel soot.展开更多
La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry（XRD）, X-ray Photoelectron Spectros...La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry（XRD）, X-ray Photoelectron Spectroscopy（XPS） and Scanning Electron Microscopy（SEM）. XPS analyses reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La3+ being substituted by Cu2+ . Temperature-programmed-desorption（TPD） and temperature-programmed-reduction（TPR） analyses were carried out to study the catalytic behavior. It is found that there are two O2-desorption peaks at 350℃ and 650℃ in the TPD pattern, and two CH4-consumption peaks at 420℃ and 750℃ in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. The catalytic activity tests were performed in a fixed-bed reactor, and the results show that the T<sup>1/2 at which the conversion of methane attains 50% of La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is lower by 55℃ than that of LaMnO3. This indicates that the catalytic activity of-La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is increased with partial substitution of Cu2+ for La3+ .-展开更多
In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammoniu...In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–guest inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.展开更多
Methyl-（γ-chloropropyl）dichlorosilane was synthesized under the catalysis of a silicasupported Karstedt-type catalyst. By orthogonal experimental design method, the optimum reaction parameters such as reactants rat...Methyl-（γ-chloropropyl）dichlorosilane was synthesized under the catalysis of a silicasupported Karstedt-type catalyst. By orthogonal experimental design method, the optimum reaction parameters such as reactants ratio, reaction temperature and time, and the dosage of catalyst, were determined. At the optimum reaction condition the product yield reached 78.42%, which is higher than that reported in the literatures.展开更多
Solar‐driven thermochemical water splitting represents one efficient route to the generation of H2as a clean and renewable fuel.Due to their outstanding catalytic abilities and promising solar fuel production capacit...Solar‐driven thermochemical water splitting represents one efficient route to the generation of H2as a clean and renewable fuel.Due to their outstanding catalytic abilities and promising solar fuel production capacities,perovskite‐type redox catalysts have attracted significant attention in this regard.In the present study,the perovskite series La1‐xCaxMn1‐yAlyO3(x,y=0.2,0.4,0.6,or0.8)was fabricated using a modified Pechini method and comprehensively investigated to determine the applicability of these materials to solar H2production via two‐step thermochemical water splitting.The thermochemical redox behaviors of these perovskites were optimized by doping at either the A(Ca)or B(Al)sites over a broad range of substitution values,from0.2to0.8.Through this doping,a highly efficient perovskite(La0.6Ca0.4Mn0.6Al0.4O3)was developed,which yielded a remarkable H2production rate of429μmol/g during two‐step thermochemical H2O splitting,going between1400and1000°C.Moreover,the performance of the optimized perovskite was found to be eight times higher than that of the benchmark catalyst CeO2under the same experimental conditions.Furthermore,these perovskites also showed impressive catalytic stability during two‐step thermochemical cycling tests.These newly developed La1‐xCaxMn1‐yAlyO3redox catalysts appear to have great potential for future practical applications in thermochemical solar fuel production.展开更多
In order to synthesize high-quality type-Ⅱa large diamond, the selection of catalyst is very important, in addition to the nitrogen getter. In this paper, type-IIa large diamonds are grown under high pressure and hig...In order to synthesize high-quality type-Ⅱa large diamond, the selection of catalyst is very important, in addition to the nitrogen getter. In this paper, type-IIa large diamonds are grown under high pressure and high temperature（HPHT） by using the temperature gradient method（TGM）, with adopting Ti/Cu as the nitrogen getter in Ni70Mn25Co5（abbreviated as NiMnCo） or Fe（55）Ni（29）Co（16）（abbreviated FeNiCo） catalyst. The values of nitrogen concentration（Nc） in both synthesized high-quality diamonds are less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo or Ti/Cu（1.8 wt%） is added in the NiMnCo. The difference in solubility of nitrogen between both catalysts at HPHT is the basic reason for the different effect of Ti/Cu on eliminating nitrogen. The nitrogen-removal efficiency of Ti/Cu in the NiMnCo catalyst is less than in the FeNiCo catalyst. Additionally, a high-quality type-Ⅱa large diamond size of 5.0 mm is obtained by reducing the growth rate and keeping the nitrogen concentration of the diamond to be less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo catalyst.展开更多
Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the cor...Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the corresponding products in high yields.展开更多
Catalytic activities for direct NO decomposition were investigated over C-type cubic Y2O3–Tb4O7–ZrO2 prepared by a coprecipitation method. The NO decomposition activity was enhanced by partial substitution of the yt...Catalytic activities for direct NO decomposition were investigated over C-type cubic Y2O3–Tb4O7–ZrO2 prepared by a coprecipitation method. The NO decomposition activity was enhanced by partial substitution of the yttrium sites with terbium in a (Y0.97Zr0.03)2O3.03 catalyst, which shows high NO decomposition activity. Among the catalysts synthesized in this study, the (Y0.67Tb0.30Zr0.03)2O3.33 catalyst exhibited the highest NO decomposition activity;NO conversion to N2 was as high as 67% at 900℃ in the absence of O2 (NO/He atmosphere), and a relatively high conversion ratio was observed even in the presence of O2 or CO2, compared with those obtained over conventional direct NO decomposition catalysts. These results indicate that the C-type cubic Y2O3–Tb4O7–ZrO2 catalyst is a new potential candidate for direct NO decomposition.展开更多
文摘Significant scientific and economic benefits may be derived from investigating the best choice of catalyst in the alkyd resin synthesis. The effect of catalyst type and concentration on the production of alkyd resin using castor seed oil (CSO) was evaluated. Lithium hydroxide, lead (II) oxide, calcium carbonate, sodium hydroxide and calcium oxide were investigated. The fatty acid profile of the raw CSO was determined using GC-MS while structural elucidation of the CSO based alkyd resins was determined using FTIR spectrometry. The CSO modified alkyd resin produced has acid values of 5.0, 5.61, 7.0 8.24 and 11 for lithium hydroxide, lead (II) oxide, calcium carbonate, sodium hydroxide and calcium oxide respectively. The extent of reaction was 95%, 95%, 91%, 89% and 88% for lithium hydroxide, lead (II) oxide, calcium carbonate, sodium hydroxide and calcium oxide respectively at the reaction time of 150 minutes. The alcoholysis reaction completion time was fastest in LiOH followed by PbO, CaCO<sub>3</sub>, NaOH and CaO catalyst. Physico-chemical parameters of the oil and performance evaluation of the alkyd films suggest that they are sustainable materials for surface coating. LiOH shows excellent robustness to expanded process parameters.
文摘A series of perovskite type oxides and supported Ag catalysts were prepared, and characterized by X ray diffraction (XRD) and X ray photoelectron spectroscopy (XPS). The catalytic activities of the catalysts as well as influencing factors on catalytic activity have been investigated for the simultaneous removal of NOx and diesel soot particulate. An increase in catalytic activity for the selective reduction of NOx was observed with Ag addition in these perovskite oxides, especially with 5% Ag loading. This catalyst could be a promising candidate of catalytic material for the simultaneous elimination of NOx and diesel soot.
文摘La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ perovskite-type catalyst for methane combustion prepared through sol-gel process was characterized by X-ray Diffractometry（XRD）, X-ray Photoelectron Spectroscopy（XPS） and Scanning Electron Microscopy（SEM）. XPS analyses reveal that the surface characteristics of the catalyst are changed. The lattice defects and oxygen vacancies on the catalyst surface are enhanced due to a part of La3+ being substituted by Cu2+ . Temperature-programmed-desorption（TPD） and temperature-programmed-reduction（TPR） analyses were carried out to study the catalytic behavior. It is found that there are two O2-desorption peaks at 350℃ and 650℃ in the TPD pattern, and two CH4-consumption peaks at 420℃ and 750℃ in the TPR patterns respectively, which indicates that the two kinds of oxygen species, so-called α and β oxygen, can react with the methane during catalytic combustion process. The catalytic activity tests were performed in a fixed-bed reactor, and the results show that the T<sup>1/2 at which the conversion of methane attains 50% of La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is lower by 55℃ than that of LaMnO3. This indicates that the catalytic activity of-La<sup>0.8 Cu<sup>0.2 MnO<sup>3±δ is increased with partial substitution of Cu2+ for La3+ .-
文摘In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–guest inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.
基金support from the National Natural Science Foundation of China(No.50473036)
文摘Methyl-（γ-chloropropyl）dichlorosilane was synthesized under the catalysis of a silicasupported Karstedt-type catalyst. By orthogonal experimental design method, the optimum reaction parameters such as reactants ratio, reaction temperature and time, and the dosage of catalyst, were determined. At the optimum reaction condition the product yield reached 78.42%, which is higher than that reported in the literatures.
基金supported by the Australian Research Council(FT120100913)the National Natural Science Foundation of China(51372248,51432009)~~
文摘Solar‐driven thermochemical water splitting represents one efficient route to the generation of H2as a clean and renewable fuel.Due to their outstanding catalytic abilities and promising solar fuel production capacities,perovskite‐type redox catalysts have attracted significant attention in this regard.In the present study,the perovskite series La1‐xCaxMn1‐yAlyO3(x,y=0.2,0.4,0.6,or0.8)was fabricated using a modified Pechini method and comprehensively investigated to determine the applicability of these materials to solar H2production via two‐step thermochemical water splitting.The thermochemical redox behaviors of these perovskites were optimized by doping at either the A(Ca)or B(Al)sites over a broad range of substitution values,from0.2to0.8.Through this doping,a highly efficient perovskite(La0.6Ca0.4Mn0.6Al0.4O3)was developed,which yielded a remarkable H2production rate of429μmol/g during two‐step thermochemical H2O splitting,going between1400and1000°C.Moreover,the performance of the optimized perovskite was found to be eight times higher than that of the benchmark catalyst CeO2under the same experimental conditions.Furthermore,these perovskites also showed impressive catalytic stability during two‐step thermochemical cycling tests.These newly developed La1‐xCaxMn1‐yAlyO3redox catalysts appear to have great potential for future practical applications in thermochemical solar fuel production.
基金supported by the National Natural Science Foundation of China(Grant No.11604246)the China Postdoctoral Science Foundation(Grant No.2016M592714)+2 种基金the Professional Practice Demonstration Base for Professional Degree Graduate in Material Engineering of Henan Polytechnic University,China(Grant No.2016YJD03)the Funds from the Education Department of Henan Province,China(Grant Nos.12A430010 and 17A430020)the Project for Key Science and Technology Research of Henan Province,China(Grant No.162102210275)
文摘In order to synthesize high-quality type-Ⅱa large diamond, the selection of catalyst is very important, in addition to the nitrogen getter. In this paper, type-IIa large diamonds are grown under high pressure and high temperature（HPHT） by using the temperature gradient method（TGM）, with adopting Ti/Cu as the nitrogen getter in Ni70Mn25Co5（abbreviated as NiMnCo） or Fe（55）Ni（29）Co（16）（abbreviated FeNiCo） catalyst. The values of nitrogen concentration（Nc） in both synthesized high-quality diamonds are less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo or Ti/Cu（1.8 wt%） is added in the NiMnCo. The difference in solubility of nitrogen between both catalysts at HPHT is the basic reason for the different effect of Ti/Cu on eliminating nitrogen. The nitrogen-removal efficiency of Ti/Cu in the NiMnCo catalyst is less than in the FeNiCo catalyst. Additionally, a high-quality type-Ⅱa large diamond size of 5.0 mm is obtained by reducing the growth rate and keeping the nitrogen concentration of the diamond to be less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo catalyst.
文摘Mannich-type reactions of aldimines with silyl enolates and hetero Diels-Alder reactions of aldehydes with Danishef-sky’s diene in the presence of anion catalysts derived from proline were performed to afford the corresponding products in high yields.
文摘Catalytic activities for direct NO decomposition were investigated over C-type cubic Y2O3–Tb4O7–ZrO2 prepared by a coprecipitation method. The NO decomposition activity was enhanced by partial substitution of the yttrium sites with terbium in a (Y0.97Zr0.03)2O3.03 catalyst, which shows high NO decomposition activity. Among the catalysts synthesized in this study, the (Y0.67Tb0.30Zr0.03)2O3.33 catalyst exhibited the highest NO decomposition activity;NO conversion to N2 was as high as 67% at 900℃ in the absence of O2 (NO/He atmosphere), and a relatively high conversion ratio was observed even in the presence of O2 or CO2, compared with those obtained over conventional direct NO decomposition catalysts. These results indicate that the C-type cubic Y2O3–Tb4O7–ZrO2 catalyst is a new potential candidate for direct NO decomposition.
