The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40（40%）/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modifi...The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40（40%）/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modification of H3PW12O40（40%）/SiO2 gave the most promising result of 20% dimethyl ether conversion and 34.8% dimethoxymethane selectivity. Dimethoxymethane could be synthe- sized via methoxy groups decomposed from dimethyl ether through the synergistic effect between the acid sites and the redox sites of Cs modified H3PW12O40（40%）/SiO2.展开更多
Two novel heteroatom-bridged his (benzo-12-crown-4 ether)s, i.e. his [2-nitro-4,5 (1,4,7,10-tetraoxadecamethylene) disulfide 1 and diselenide 2, have been synthesized. X ray crystallographic structure was obtained for...Two novel heteroatom-bridged his (benzo-12-crown-4 ether)s, i.e. his [2-nitro-4,5 (1,4,7,10-tetraoxadecamethylene) disulfide 1 and diselenide 2, have been synthesized. X ray crystallographic structure was obtained for 1. Ion selective electrodes (ISE) for Ag+, containing 1 and 2 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag^+ (K_(Ag.M)^(pot)) were determined against other heavy metal ions, alkali and alkaline-earth metal ions. and ammonium ion. These ISEs showed excellent Ag^+ selectivities, log K_(Ag.M)^(pot) ≤ -3.8, against most of the interfering canons examined, except for Hg^+.展开更多
A kind of Keggin structural 12-WP acid was prepared and used as catalyst to synthesize methyl tert-butyl ether(MTBE) from methanol and tert-butanol.The influences of the amount of 12-WP acid,the ratio of reactants and...A kind of Keggin structural 12-WP acid was prepared and used as catalyst to synthesize methyl tert-butyl ether(MTBE) from methanol and tert-butanol.The influences of the amount of 12-WP acid,the ratio of reactants and reaction temperature on the yield of MTBE were investigated.The results showed that the conversion of tert-butanol,selectivity of MTBE and the yield of MTBE could be up to 59.6%,74.5% and 44.4%,respectively when the amount of 12-WP acid was 2.16% of tert-butanol and the mole ratio of tert-butanol to methanol was 1:1.2 at 100 ℃.展开更多
基金Foundation items:the National Natural Science Foundation of China(No.20373085)the Natural Science Foundation of Shanxi Province(No.20051023)
文摘The attractive utilization route for one-step catalytic oxidation of dimethyl ether to dimethoxymethane was successfully carried out over the H3PW12O40（40%）/SiO2 catalyst, modified by Cs, K, Ni, and V. The Cs modification of H3PW12O40（40%）/SiO2 gave the most promising result of 20% dimethyl ether conversion and 34.8% dimethoxymethane selectivity. Dimethoxymethane could be synthe- sized via methoxy groups decomposed from dimethyl ether through the synergistic effect between the acid sites and the redox sites of Cs modified H3PW12O40（40%）/SiO2.
文摘Two novel heteroatom-bridged his (benzo-12-crown-4 ether)s, i.e. his [2-nitro-4,5 (1,4,7,10-tetraoxadecamethylene) disulfide 1 and diselenide 2, have been synthesized. X ray crystallographic structure was obtained for 1. Ion selective electrodes (ISE) for Ag+, containing 1 and 2 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag^+ (K_(Ag.M)^(pot)) were determined against other heavy metal ions, alkali and alkaline-earth metal ions. and ammonium ion. These ISEs showed excellent Ag^+ selectivities, log K_(Ag.M)^(pot) ≤ -3.8, against most of the interfering canons examined, except for Hg^+.
文摘A kind of Keggin structural 12-WP acid was prepared and used as catalyst to synthesize methyl tert-butyl ether(MTBE) from methanol and tert-butanol.The influences of the amount of 12-WP acid,the ratio of reactants and reaction temperature on the yield of MTBE were investigated.The results showed that the conversion of tert-butanol,selectivity of MTBE and the yield of MTBE could be up to 59.6%,74.5% and 44.4%,respectively when the amount of 12-WP acid was 2.16% of tert-butanol and the mole ratio of tert-butanol to methanol was 1:1.2 at 100 ℃.
