Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalys...Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.展开更多
This article describes the solubility data of the quaternary systems of CsCl LaCl 3 HCl H 2O(25 ℃, HCl 13% or 23%(wt)) and CsCl LaCl 3 HAc H 2O(30 ℃, HAc 42%(wt)), and the corresponding solubility equilibr...This article describes the solubility data of the quaternary systems of CsCl LaCl 3 HCl H 2O(25 ℃, HCl 13% or 23%(wt)) and CsCl LaCl 3 HAc H 2O(30 ℃, HAc 42%(wt)), and the corresponding solubility equilibrium diagrams. Three new compounds, CsCl·LaCl 3·4H 2O, 2CsCl·LaCl 3·2H 2O and 3CsCl·LaCl 3·3H 2O have been found. From analysis of the systems by the X ray powder diffraction, TG DTG and DTA, the properties of the compounds are presented. The interpretation of the mechanism of Meyer′s reactions is discussed further and the synthesis method of four type new compounds is offered.展开更多
The equilibrium solubilities of the quaternary system CsCl-TmCl3-HCl-H2O was determined at 25 ℃ and the corresponding equilibrium diagram was constructed. The diagram is a complicated system with limited solid soluti...The equilibrium solubilities of the quaternary system CsCl-TmCl3-HCl-H2O was determined at 25 ℃ and the corresponding equilibrium diagram was constructed. The diagram is a complicated system with limited solid solutions and formation of a new compound 3CsCl·2TmCl3·14H2O. The new compound has been characterized by XRD, TC-DTG and fluorescence spectrometry. Results show that upconversion spectrum exhibits at 335 nm when exciting at 860 nm, and fluorescence spectrum exhibits at 295 nm and 385 nm when exciting at 240 nm. The compound loses its crystal water by four steps at 50 to 250 ℃. Using a heat conduction calorimeter, the standard molar enthalpy of dissolution of 3CsCl·2TmCl3·14H2O was determined to be (-11.601 ± 0.050) kJ·mol-1 at 298.15 K.展开更多
文摘Activated carbon-supported mercuric chloride（HgCl2） is used as an industrial catalyst for acetylene hydrochlorination. However, the characteristic of easy sublimation of HgCl2 leads to the deactivation o the catalyst. Here, we showed that the thermal stability of the Hg/AC catalyst can be evidently improved when Cs Cl is added into the Hg/AC catalyst. Compared with the pure Hg/AC catalyst, the sublimation rate of HgCl2 from the Hg–Cs/AC catalyst decreased significantly and the Hg–Cs/AC catalyst showed bette catalytic activity and stability in the reaction. This promoting effect is related to the existence of cesium mercuric chlorides（CsxHgyCl（x＋2y）） highlighted by XRD, HR-TEM and EDX analyses. Thus, reacting HgCl2 with alkali chlorides to form alkali-mercuric chlorides may be a key to design highly efficient and thermally stable mercuric chloride catalyst for hydrochlorination reactions.
文摘This article describes the solubility data of the quaternary systems of CsCl LaCl 3 HCl H 2O(25 ℃, HCl 13% or 23%(wt)) and CsCl LaCl 3 HAc H 2O(30 ℃, HAc 42%(wt)), and the corresponding solubility equilibrium diagrams. Three new compounds, CsCl·LaCl 3·4H 2O, 2CsCl·LaCl 3·2H 2O and 3CsCl·LaCl 3·3H 2O have been found. From analysis of the systems by the X ray powder diffraction, TG DTG and DTA, the properties of the compounds are presented. The interpretation of the mechanism of Meyer′s reactions is discussed further and the synthesis method of four type new compounds is offered.
文摘The equilibrium solubilities of the quaternary system CsCl-TmCl3-HCl-H2O was determined at 25 ℃ and the corresponding equilibrium diagram was constructed. The diagram is a complicated system with limited solid solutions and formation of a new compound 3CsCl·2TmCl3·14H2O. The new compound has been characterized by XRD, TC-DTG and fluorescence spectrometry. Results show that upconversion spectrum exhibits at 335 nm when exciting at 860 nm, and fluorescence spectrum exhibits at 295 nm and 385 nm when exciting at 240 nm. The compound loses its crystal water by four steps at 50 to 250 ℃. Using a heat conduction calorimeter, the standard molar enthalpy of dissolution of 3CsCl·2TmCl3·14H2O was determined to be (-11.601 ± 0.050) kJ·mol-1 at 298.15 K.
