采用常压微反、程序升温还原(TPR)、程序升温硫化(TPS)及原位红外光谱(IR)等技术,对Co Mo Al2O3催化剂的表征研究发现:在Co Mo Al2O3催化剂中不仅存在着Co、Mo中心,而且存在由Co、Mo相互作用产生的中心,Co Mo Al2O3催化剂的催化性能是...采用常压微反、程序升温还原(TPR)、程序升温硫化(TPS)及原位红外光谱(IR)等技术,对Co Mo Al2O3催化剂的表征研究发现:在Co Mo Al2O3催化剂中不仅存在着Co、Mo中心,而且存在由Co、Mo相互作用产生的中心,Co Mo Al2O3催化剂的催化性能是由Co、Mo中心和Co、Mo相互作用产生的中心共同作用的结果。展开更多
The two Co sites are well characterized in reduced Co-Mo/Al_2O_3 and Ru-Co- Mo/Al_2O_3 by new bands at 1895 and 1880 cm^(-1)in the IR spectra due to NO adsorption.
An investigation on adsorption of NO on reduced Co-Mo/Al_2O_3 and Ru-Co-Mo/Al_2O_3 catalysts has been performed using FT-IR and MS spectroscopies. IR spectra of NO adsorption showed two bands at 1895 and 1800 cm_(-1),...An investigation on adsorption of NO on reduced Co-Mo/Al_2O_3 and Ru-Co-Mo/Al_2O_3 catalysts has been performed using FT-IR and MS spectroscopies. IR spectra of NO adsorption showed two bands at 1895 and 1800 cm_(-1), and NO--TPD profiles gave rise to several peaks at 353, 423 and 473 K, which are assigned to various Co-sites on the surface. Compared with Co-Mo/Al_2O_3, the adsorption rate, binding energy, and amount of NO adsorbed on Ru-Co-Mo/Al_2O_3 are very high.展开更多
A series of CoMo/Al2O3 catalysts for selective hydrodesulfurization （HDS） of gasoline were studied with Raman spectroscopy, a powerful method that creates specific signals for the states and the distributions of oxi...A series of CoMo/Al2O3 catalysts for selective hydrodesulfurization （HDS） of gasoline were studied with Raman spectroscopy, a powerful method that creates specific signals for the states and the distributions of oxidic precursors and sulfided active phases. The higher the Mo and Co, the lower the tetrahedrally coordinated molybdate, and the higher the polymolybdate. But the amount of polymolybdate decreased when CoMoO4 appeared. Cobalt-promoted polymolybdate was the precursor, and its relative content correlated well with the HDS selectivity. For sulfided catalysts, adding the cobalt-promoter led to local distortion-disorder of the MoS2 structure and the formation of a CoMoS phase. This method can provide important information for designing new industrial selective-HDS catalvsts.展开更多
The effects of reaction temperature, partial pressure of methane, catalyst weight and gas hourly space velocity （GHSV） on methane decomposition were reported. The decomposition reaction was performed in a vertical f...The effects of reaction temperature, partial pressure of methane, catalyst weight and gas hourly space velocity （GHSV） on methane decomposition were reported. The decomposition reaction was performed in a vertical fixed-bed reactor over 8Co-2Mo/Al 2 O 3 catalyst. The experimental results show that these four process parameters studied had vital effects on carbon yield. As revealed by the electron microscopy and Raman spectroscopy analyses, the reaction temperature and GHSV governed the average diameter, the diameter distribution and the degree of graphitization of the synthesized carbon nanotubes （CNTs）. Also, an evidence is presented to show that higher temperatures and higher GHSV favored the formation of better-graphitized CNTs with larger diameters.展开更多
The halide-activated pack cementation method is utilized to codeposit aluminum and silicon on Mo substrate. Emphasis is placed on the microstructure and elevated-temperature oxidation resistance of coatings. The resul...The halide-activated pack cementation method is utilized to codeposit aluminum and silicon on Mo substrate. Emphasis is placed on the microstructure and elevated-temperature oxidation resistance of coatings. The results show that hexagonal Mo(Si, Al)2 as a main phase and a little amount of the lower disilicide Mo5Si3 was formed on Mo substrate through the halide-activated pack cementation method. The resultant Si-Al coating on Mo substrate exhibits excellent cyclic oxidation resistance. The excellent cyclic oxidation resistance of the coatings is attributed to the formation of alumina on the coatings during the oxidation.展开更多
This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) ...This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) Ulva lactuca (Easters-Scheldt, the Netherlands). Mechanical pressure at 10 bar of fresh seaweed fronds casu quo biomass in the laboratory delivered seaweed moisture which was analyzed by Inductively Coupled Plasma Spectroscopy (ICP)-techniques for heavy-metals = [HM], (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb & Zn). Three important observations were made: 1) The [HM] in the seaweed moisture is higher than in the surrounding seawater which directs to mechanism(s) of bio-accumulation;2) The accumulation factor [AF] is varying per metallic-cation with an overall trend for our four seaweeds and sampling locations for [HM] are: As & Co & Cu: 5000 - 10,000 μg/l;Ni & Zn: 3000 - 5000 μg/l;Cd: 2000 - 3000 μg/l;Cr: 1000 - 2000 μg/l;Al: 200 - 1000 μg/l;Mo & Pb & Fe: 0 - 200 μg/l range. 3) Seaweed moisture detected that [HM]: Pb & Zn & Fe—which all three could not be detected in the seawater—supports the view that seaweeds have a preference in their bio-accumulation mechanism for these three HM. Major conclusion is in general that “overall” for the macro-elements Ca, Fe, K, Mg, Mn, Na, P & S in the moisture of the four seaweed species the concentration is lower in the seaweed species, or equals the concentration, in comparison to the surrounding sea water. For the HM (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) the opposite is the case species and is the concentration “overall” higher in the seaweed species in comparison to the surrounding sea water. Further topics addressed include strategies of irrigation of the Sahara desert with the moisture out of seaweeds under conditions of low anthropogenic influences.展开更多
目的通过电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)法建立加味左金丸中Cd、Pb、As、Hg、Co、V、Ni、Cu、Li、Sb、Ba、Mo、Sn、Cr、Na、Mg、Al、Ca、Ti、Mn、Fe、Zn、Ga、Se、Sr、Tl共计26种无机元素...目的通过电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)法建立加味左金丸中Cd、Pb、As、Hg、Co、V、Ni、Cu、Li、Sb、Ba、Mo、Sn、Cr、Na、Mg、Al、Ca、Ti、Mn、Fe、Zn、Ga、Se、Sr、Tl共计26种无机元素的测定方法。方法加味左金丸通过微波消解法处理后,根据相对分子质量的大小选择内标物,其中^(7)Li、^(23)Na、^(24)Mg、^(27)Al、^(40)Ca、^(48)Ti、^(51)V、^(52)Cr、^(55)Mn、^(56)Fe、^(58)Ni、^(59)Co、^(63)Cu、^(66)Zn、^(70)Ga、^(75)As、^(77)Se、^(86)Sr以^(72)Ge作为内标;^(95)Mo、^(114)Cd、^(118)Sn、^(121)Sb、^(137)Ba以^(115)In作为内标;^(202)Hg、^(205)Tl、^(208)Pb以^(209)Bi作为内标。对标准品溶液、空白溶液与供试品溶液进行分析,采用标准曲线法进行定量分析。通过ICP-MS法进行测定。结果26种无机元素线性的相关系数r≥0.9996,检出限为0.001~1.500μg/L,定量限为0.01~5.00μg/L,精密度与重复性试验的RSD均小于5%,平均回收率在82.64%~106.44%,RSD均小于5%。对3个厂家的12批样品进行了测定,26种元素的含量差异较大,其中Na、Mg、Ca、Fe 4种元素的含量比较高,均大于500μg/g,Cd、Pb、As、Hg、Co、Li、Sb、Mo、Sn、Cr、Se、Tl的含量比较低,均小于1μg/g。由结果可知,人体的常量元素,如Na、Mg、Ca的含量比较高,Cd、Pb、As、Hg等有害元素含量比较低。根据《中国药典》2020年版一部的要求,本品中Cd、Pb、As、Hg与Cu均符合规定。结论该方法快速、准确,可以用于加味左金丸中无机元素的测定。展开更多
文摘采用常压微反、程序升温还原(TPR)、程序升温硫化(TPS)及原位红外光谱(IR)等技术,对Co Mo Al2O3催化剂的表征研究发现:在Co Mo Al2O3催化剂中不仅存在着Co、Mo中心,而且存在由Co、Mo相互作用产生的中心,Co Mo Al2O3催化剂的催化性能是由Co、Mo中心和Co、Mo相互作用产生的中心共同作用的结果。
文摘The two Co sites are well characterized in reduced Co-Mo/Al_2O_3 and Ru-Co- Mo/Al_2O_3 by new bands at 1895 and 1880 cm^(-1)in the IR spectra due to NO adsorption.
基金Natural Science Foundation of Chinese Academy of Sciences.
文摘An investigation on adsorption of NO on reduced Co-Mo/Al_2O_3 and Ru-Co-Mo/Al_2O_3 catalysts has been performed using FT-IR and MS spectroscopies. IR spectra of NO adsorption showed two bands at 1895 and 1800 cm_(-1), and NO--TPD profiles gave rise to several peaks at 353, 423 and 473 K, which are assigned to various Co-sites on the surface. Compared with Co-Mo/Al_2O_3, the adsorption rate, binding energy, and amount of NO adsorbed on Ru-Co-Mo/Al_2O_3 are very high.
基金funding of the State Key Project (Nos. 2012CB224802 and 2012BAE05B03)the SINOPEC Project (No. 111015)
文摘A series of CoMo/Al2O3 catalysts for selective hydrodesulfurization （HDS） of gasoline were studied with Raman spectroscopy, a powerful method that creates specific signals for the states and the distributions of oxidic precursors and sulfided active phases. The higher the Mo and Co, the lower the tetrahedrally coordinated molybdate, and the higher the polymolybdate. But the amount of polymolybdate decreased when CoMoO4 appeared. Cobalt-promoted polymolybdate was the precursor, and its relative content correlated well with the HDS selectivity. For sulfided catalysts, adding the cobalt-promoter led to local distortion-disorder of the MoS2 structure and the formation of a CoMoS phase. This method can provide important information for designing new industrial selective-HDS catalvsts.
基金supported by the Malaysian Technology Development Corporation (MTDC) under the Commercialization of Research & Development Fund (CRDF) (Project A/C No. MBF065-USM/05)the Monash Internal Seed Grant (A/C no: E-9-09)
文摘The effects of reaction temperature, partial pressure of methane, catalyst weight and gas hourly space velocity （GHSV） on methane decomposition were reported. The decomposition reaction was performed in a vertical fixed-bed reactor over 8Co-2Mo/Al 2 O 3 catalyst. The experimental results show that these four process parameters studied had vital effects on carbon yield. As revealed by the electron microscopy and Raman spectroscopy analyses, the reaction temperature and GHSV governed the average diameter, the diameter distribution and the degree of graphitization of the synthesized carbon nanotubes （CNTs）. Also, an evidence is presented to show that higher temperatures and higher GHSV favored the formation of better-graphitized CNTs with larger diameters.
文摘The halide-activated pack cementation method is utilized to codeposit aluminum and silicon on Mo substrate. Emphasis is placed on the microstructure and elevated-temperature oxidation resistance of coatings. The results show that hexagonal Mo(Si, Al)2 as a main phase and a little amount of the lower disilicide Mo5Si3 was formed on Mo substrate through the halide-activated pack cementation method. The resultant Si-Al coating on Mo substrate exhibits excellent cyclic oxidation resistance. The excellent cyclic oxidation resistance of the coatings is attributed to the formation of alumina on the coatings during the oxidation.
文摘This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) Ulva lactuca (Easters-Scheldt, the Netherlands). Mechanical pressure at 10 bar of fresh seaweed fronds casu quo biomass in the laboratory delivered seaweed moisture which was analyzed by Inductively Coupled Plasma Spectroscopy (ICP)-techniques for heavy-metals = [HM], (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb & Zn). Three important observations were made: 1) The [HM] in the seaweed moisture is higher than in the surrounding seawater which directs to mechanism(s) of bio-accumulation;2) The accumulation factor [AF] is varying per metallic-cation with an overall trend for our four seaweeds and sampling locations for [HM] are: As & Co & Cu: 5000 - 10,000 μg/l;Ni & Zn: 3000 - 5000 μg/l;Cd: 2000 - 3000 μg/l;Cr: 1000 - 2000 μg/l;Al: 200 - 1000 μg/l;Mo & Pb & Fe: 0 - 200 μg/l range. 3) Seaweed moisture detected that [HM]: Pb & Zn & Fe—which all three could not be detected in the seawater—supports the view that seaweeds have a preference in their bio-accumulation mechanism for these three HM. Major conclusion is in general that “overall” for the macro-elements Ca, Fe, K, Mg, Mn, Na, P & S in the moisture of the four seaweed species the concentration is lower in the seaweed species, or equals the concentration, in comparison to the surrounding sea water. For the HM (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) the opposite is the case species and is the concentration “overall” higher in the seaweed species in comparison to the surrounding sea water. Further topics addressed include strategies of irrigation of the Sahara desert with the moisture out of seaweeds under conditions of low anthropogenic influences.
