合成了含Co ,Cu和Ni的M /Mg Al HTL类水滑石 ,并将其焙烧产物用于N2 O催化分解反应 .实验结果表明 ,Co/Mg Al HTL对N2 O分解反应的催化活性明显高于Cu/Mg Al HTL和Ni/Mg Al HTL的活性 .在保持样品中Al含量不变的条件下 ,催化活性随着Co...合成了含Co ,Cu和Ni的M /Mg Al HTL类水滑石 ,并将其焙烧产物用于N2 O催化分解反应 .实验结果表明 ,Co/Mg Al HTL对N2 O分解反应的催化活性明显高于Cu/Mg Al HTL和Ni/Mg Al HTL的活性 .在保持样品中Al含量不变的条件下 ,催化活性随着Co含量的增加及Mg含量的减少而升高 ,各催化剂的活性顺序为 :Co/Al HTL >Co/Mg Al HTL >Cu/Mg Al HTL >Ni/Mg Al HTL .在此基础上 ,进一步考察了Co/Al HTL中Co/Al原子比调变对催化剂活性的影响 .对含Co类水滑石及其焙烧产物进行了XRF ,XRD和N2 O TPD表征 .结果表明 ,含Co类水滑石具有典型的水滑石结构 ,其高温焙烧产物都含尖晶石相 .由于尖晶石相中Co O Al活性中心的作用 ,含Co类水滑石对N2 O分解反应表现出较高的催化活性 .随着Co/Al原子比的增大 ,含Co类水滑石焙烧产物的尖晶石相特征更加突出 ,Co O Al活性中心数目随之增多 ,催化剂的活性也相应升高 .展开更多
Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was inves...Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was investigated with dry reforming of methane.Experimental results showed that the hydrotalcite-like precursors could be completely decomposed and partly reduced by cold plasma jet,and the Nicontained catalysts exhibited much higher activity than the catalyst without Ni.Especially,the catalyst with Ni/Co ratio of 8/2 achieved not only the highest conversions of 80.3%and 69.3%for CH4 and CO2,respectively,but also the best stability in 100 h testing.The catalysts were characterized by XRD,XPS,TEM and N2 adsorption techniques,and the results showed that the better performance of the 8Ni2Co bimetallic catalyst was attributed to its higher metal dispersion,smaller metal particle size,as well as the interaction effect between Ni and Co,which were brought by the special catalyst preparation method.展开更多
A series of calcined HTLcs catalysts were prepared and modified with potassium phosphate by impregnation method to clarify the influence of catalyst alkalinity on the side chain alkylation of toluene with methanol for...A series of calcined HTLcs catalysts were prepared and modified with potassium phosphate by impregnation method to clarify the influence of catalyst alkalinity on the side chain alkylation of toluene with methanol for synthesis of ethylbenzene and styrene.The catalysts were characterized by X-ray diffraction(XRD),N_(2)physical adsorption-desorption,Fourier-transform infrared spectroscopy(FT-IR),Scanning electron microscopy(SEM),X-ray photoelectron spectrometry(XPS),NH_(3)temperature-programmed desorption(NH_(3)-TPD)and CO_(2)temperature-programmed desorption(CO_(2)-TPD).It was found that the selectivity of styrene was highest(39.25%)when the K_(3)PO_(4)loading was 7.5 wt%.And the total yield of styrene and ethylbenzene could reach 65.08%with 10 wt%K_(3)PO_(4)loading.This might due to the fact that the addition of K_(3)PO_(4)could adjust the acid and basic sites of catalysts.In addition,appropriate strength and amount of basic sites were favorable to producing more styrene.展开更多
A novel strong-fluorescent hydrotalcite-like compound (Al-HTLc) was synthesized by coprecipitation. In the sample, the content of aluminum(III) in the layers was decreased to a proper value. The Al3+ ions coordinated ...A novel strong-fluorescent hydrotalcite-like compound (Al-HTLc) was synthesized by coprecipitation. In the sample, the content of aluminum(III) in the layers was decreased to a proper value. The Al3+ ions coordinated with 8-hydroxyquinolines (8-HQ) which were dispersed into the anions in the interlayer region. The sample was characterized by XRD, XPS, FT-IR, TG-DSC, UV-Vis, and fluorescence spec- troscopy; its composition and structure were also determined. The results indicate that the sample can emit fluorescence (487 nm) with a strong fluorescence intensity (4.9×105 (a.u.)). The fluorescent lifetime and fluorescence quantum yield of Al-HTLc were measured to be 21.24 ns and 67%, respectively, higher than those of pure 8-hydroxyquinoline aluminum (Alq3). The result of TG-DSC measurement clearly shows the enhanced thermal stability of Al-HTLc compared with that of MgAl-LDH and pure Alq3. Al-HTLc may be used as a novel luminescent functional material.展开更多
A novel strong-fluorescent Eu-containing hydrotalcite-like compound (Eu-HTlc) was synthesized using the coprecipitation method,in which aluminum(III) was partially substituted by Europium (III) in the hydrotalcite-lik...A novel strong-fluorescent Eu-containing hydrotalcite-like compound (Eu-HTlc) was synthesized using the coprecipitation method,in which aluminum(III) was partially substituted by Europium (III) in the hydrotalcite-like layers,and thenoyltrifluoroacetone,1,10-phenanthroline were dispersed into the anions in the interlayer region.The sample was characterized by XRD,XPS,FT-IR,ICP,TG-DSC,TEM and fluorescence spectra,and its composition and structure were determined.The results indicated that the sample exhibited a characteristic red light (614 nm).The fluorescent lifetime and fluorescence quantum yield of Eu-HTlc were measured to be respectively 893 -s and 66.44%,higher than those of Eu(III)-thenoyltrifluoroacetone1,10-phenanthroline complex [Eu(TTA)3phen].The result of TG-DSC measurement showed the enhanced thermal stability of Eu-HTlc compared with that of MgAl-LDHs and Eu(TTA)3phen.With excellent photoluminescent property and thermal stability,low contents of rare earth ions and ligands,the Eu-HTlc may become one of the novel fluorescent materials with potential applications.展开更多
Hydrotalcite-like compound （HTlc） with a Mg/AI molar ratio of 2 ： 1 was synthesized by using a coprecipitation method and the sorption removal of Cu（Ⅱ） by the Mg-AI HTlc sample from CuSO4 solution was investigat...Hydrotalcite-like compound （HTlc） with a Mg/AI molar ratio of 2 ： 1 was synthesized by using a coprecipitation method and the sorption removal of Cu（Ⅱ） by the Mg-AI HTlc sample from CuSO4 solution was investigated. It was found that the Mg-AI HTlc showed a good sorption ability for Cu（Ⅱ） from CuSO4 solution, indicating that the use of hydrotalcite-like compounds as promising inorganic sorbents for the removal of heavy metal ions from water is possible. The sorption kinetics and the sorption isotherm of Cu（Ⅱ） on the HTlc obeyed the pseudo-second order kinetic model and Langmuir equation, respectively. The percent removal of Cu（Ⅱ） by the HT1c was strongly dependent on the initial pH of bulk solution. It increased sharply with the increase of initial pH value in the range of 5-7, and was relatively small in the initial pH range of 4-5, while it reached about 100% after initial pH was higher than 7. The presence of AlCl3 might obviously lower the equilibrium sorption amount （qc） of Cu（Ⅱ） on the HTlc. However, the presences of NaCI and MgCl2 might increase the qe. The presences of ligands （citric acid and EDTA） in the studied concentration range might obviously decrease the qe of Cu（Ⅱ） on the HT1c. The removal mechanism of Cu（Ⅱ） cations by HTlc in the presence of SO4^2- anions may be attributed to the surface-induced precipitation of Cu（Ⅱ） hydroxides and the surface complex adsorption by the linking effect of SO4^2- between the HTlc and Cu（Ⅱ） cations, and the removal ability arising from the surface-induced precipitation is much higher than that from the linking effect of SO4^2-.展开更多
基金supported by the National Natural Science Foundation of China(11075113)
文摘Ni-Co bimetallic catalysts with different Ni/Co content were derived from cold plasma jet decomposition and reduction of hydrotalcite-like compounds containing Ni,Co,Mg and Al,and their catalytic performance was investigated with dry reforming of methane.Experimental results showed that the hydrotalcite-like precursors could be completely decomposed and partly reduced by cold plasma jet,and the Nicontained catalysts exhibited much higher activity than the catalyst without Ni.Especially,the catalyst with Ni/Co ratio of 8/2 achieved not only the highest conversions of 80.3%and 69.3%for CH4 and CO2,respectively,but also the best stability in 100 h testing.The catalysts were characterized by XRD,XPS,TEM and N2 adsorption techniques,and the results showed that the better performance of the 8Ni2Co bimetallic catalyst was attributed to its higher metal dispersion,smaller metal particle size,as well as the interaction effect between Ni and Co,which were brought by the special catalyst preparation method.
基金financial support from the National Key Technology Research&Development Program(Grant No.2013BAC14B04)the National Natural Science Foundation of China(Grant No.21336006)+1 种基金the Shanxi Province Key Research&Development Program(international cooperation,Grant No.201803D421099)Supported by Shanxi Scholarship Council of China(Grant No.2017-035)。
文摘A series of calcined HTLcs catalysts were prepared and modified with potassium phosphate by impregnation method to clarify the influence of catalyst alkalinity on the side chain alkylation of toluene with methanol for synthesis of ethylbenzene and styrene.The catalysts were characterized by X-ray diffraction(XRD),N_(2)physical adsorption-desorption,Fourier-transform infrared spectroscopy(FT-IR),Scanning electron microscopy(SEM),X-ray photoelectron spectrometry(XPS),NH_(3)temperature-programmed desorption(NH_(3)-TPD)and CO_(2)temperature-programmed desorption(CO_(2)-TPD).It was found that the selectivity of styrene was highest(39.25%)when the K_(3)PO_(4)loading was 7.5 wt%.And the total yield of styrene and ethylbenzene could reach 65.08%with 10 wt%K_(3)PO_(4)loading.This might due to the fact that the addition of K_(3)PO_(4)could adjust the acid and basic sites of catalysts.In addition,appropriate strength and amount of basic sites were favorable to producing more styrene.
基金the National Natural Science Foundation of China (Grant No. 50272014)the Key Item of Natural Scientific Foundation of Fujian Province (Grant No. 2001F005)the Key Nano Special Item of Fujian Province (Grants No. 2005HZ01-5)
文摘A novel strong-fluorescent hydrotalcite-like compound (Al-HTLc) was synthesized by coprecipitation. In the sample, the content of aluminum(III) in the layers was decreased to a proper value. The Al3+ ions coordinated with 8-hydroxyquinolines (8-HQ) which were dispersed into the anions in the interlayer region. The sample was characterized by XRD, XPS, FT-IR, TG-DSC, UV-Vis, and fluorescence spec- troscopy; its composition and structure were also determined. The results indicate that the sample can emit fluorescence (487 nm) with a strong fluorescence intensity (4.9×105 (a.u.)). The fluorescent lifetime and fluorescence quantum yield of Al-HTLc were measured to be 21.24 ns and 67%, respectively, higher than those of pure 8-hydroxyquinoline aluminum (Alq3). The result of TG-DSC measurement clearly shows the enhanced thermal stability of Al-HTLc compared with that of MgAl-LDH and pure Alq3. Al-HTLc may be used as a novel luminescent functional material.
基金the support from the Key Nano Special Item of Fujian Province (2005HZ01-5)
文摘A novel strong-fluorescent Eu-containing hydrotalcite-like compound (Eu-HTlc) was synthesized using the coprecipitation method,in which aluminum(III) was partially substituted by Europium (III) in the hydrotalcite-like layers,and thenoyltrifluoroacetone,1,10-phenanthroline were dispersed into the anions in the interlayer region.The sample was characterized by XRD,XPS,FT-IR,ICP,TG-DSC,TEM and fluorescence spectra,and its composition and structure were determined.The results indicated that the sample exhibited a characteristic red light (614 nm).The fluorescent lifetime and fluorescence quantum yield of Eu-HTlc were measured to be respectively 893 -s and 66.44%,higher than those of Eu(III)-thenoyltrifluoroacetone1,10-phenanthroline complex [Eu(TTA)3phen].The result of TG-DSC measurement showed the enhanced thermal stability of Eu-HTlc compared with that of MgAl-LDHs and Eu(TTA)3phen.With excellent photoluminescent property and thermal stability,low contents of rare earth ions and ligands,the Eu-HTlc may become one of the novel fluorescent materials with potential applications.
基金Project supported by the Natural Science Foundation of Shandong Province of China （Nos. Z2008B08 and ZR2009BZ001）, Taishan Scholar Foundation of Shandong Province of China （No. ts20070713） and the Education Natural Science Foundation of Henan Province （No. 2010B150021 ）,
文摘Hydrotalcite-like compound （HTlc） with a Mg/AI molar ratio of 2 ： 1 was synthesized by using a coprecipitation method and the sorption removal of Cu（Ⅱ） by the Mg-AI HTlc sample from CuSO4 solution was investigated. It was found that the Mg-AI HTlc showed a good sorption ability for Cu（Ⅱ） from CuSO4 solution, indicating that the use of hydrotalcite-like compounds as promising inorganic sorbents for the removal of heavy metal ions from water is possible. The sorption kinetics and the sorption isotherm of Cu（Ⅱ） on the HTlc obeyed the pseudo-second order kinetic model and Langmuir equation, respectively. The percent removal of Cu（Ⅱ） by the HT1c was strongly dependent on the initial pH of bulk solution. It increased sharply with the increase of initial pH value in the range of 5-7, and was relatively small in the initial pH range of 4-5, while it reached about 100% after initial pH was higher than 7. The presence of AlCl3 might obviously lower the equilibrium sorption amount （qc） of Cu（Ⅱ） on the HTlc. However, the presences of NaCI and MgCl2 might increase the qe. The presences of ligands （citric acid and EDTA） in the studied concentration range might obviously decrease the qe of Cu（Ⅱ） on the HT1c. The removal mechanism of Cu（Ⅱ） cations by HTlc in the presence of SO4^2- anions may be attributed to the surface-induced precipitation of Cu（Ⅱ） hydroxides and the surface complex adsorption by the linking effect of SO4^2- between the HTlc and Cu（Ⅱ） cations, and the removal ability arising from the surface-induced precipitation is much higher than that from the linking effect of SO4^2-.
