Mesoporous silica supported Cs2.5H0.5PW12O40 catalysts were prepared by impregnation method, and several silica supports with different pore size were utilized. N2 adsorption, XRD and ICP-AES techniques were utilized ...Mesoporous silica supported Cs2.5H0.5PW12O40 catalysts were prepared by impregnation method, and several silica supports with different pore size were utilized. N2 adsorption, XRD and ICP-AES techniques were utilized to characterize the silica supports and catalysts. XRD results showed that the dispersion of Cs2.5H0.5PW12 was better for the silica support with larger pore size. The catalytic activity results showed that the pore size played important role on the catalyst activity and the molecular weight of PTHF. When Cs2.5H0.5PW12O40 was dispersed on larger pore size silica support, the catalysts showed good performances for the synthesis of PTHE The molecular weight of PTHF product on the sample in which Cs2.5H0.5PW12O40 was dispersed on larger pore support was higher than that on the catalyst with smaller pore support. The leaching amounts of the active components for the supported Cs2.5H0.5PW12O40 catalysts were much lower. After five reaction cycles, there were still good activities and stabilities for the supported Cs2.5H0.5PW12O40 catalysts with larger pore silica supports. These results were much better than those of the supported heteropolyacid H3PW12O40 catalyst.展开更多
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
基金supported by the National Natural Science Foundation of China(No.20776089)
文摘Mesoporous silica supported Cs2.5H0.5PW12O40 catalysts were prepared by impregnation method, and several silica supports with different pore size were utilized. N2 adsorption, XRD and ICP-AES techniques were utilized to characterize the silica supports and catalysts. XRD results showed that the dispersion of Cs2.5H0.5PW12 was better for the silica support with larger pore size. The catalytic activity results showed that the pore size played important role on the catalyst activity and the molecular weight of PTHF. When Cs2.5H0.5PW12O40 was dispersed on larger pore size silica support, the catalysts showed good performances for the synthesis of PTHE The molecular weight of PTHF product on the sample in which Cs2.5H0.5PW12O40 was dispersed on larger pore support was higher than that on the catalyst with smaller pore support. The leaching amounts of the active components for the supported Cs2.5H0.5PW12O40 catalysts were much lower. After five reaction cycles, there were still good activities and stabilities for the supported Cs2.5H0.5PW12O40 catalysts with larger pore silica supports. These results were much better than those of the supported heteropolyacid H3PW12O40 catalyst.
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.
