Aseries of ZnO-modified cobaltous ion exchanged ZSM-5 catalysts is prepared using incipient wetness impregnation and characterized by X-ray diffraction(XRD),N2 adsorption,transmission electron microscopy(TEM),UV-Vis d...Aseries of ZnO-modified cobaltous ion exchanged ZSM-5 catalysts is prepared using incipient wetness impregnation and characterized by X-ray diffraction(XRD),N2 adsorption,transmission electron microscopy(TEM),UV-Vis diffuse reflectance spectroscopy(DR UV-Vis),X-ray photoelectron spectroscopy(XPS),pyridine-adsorbed Fourier transform infrared(Py-IR)and Raman.Their catalytic performance towards CO_(2)-assisted dehydrogenation of ethane to ethylene has been evaluated.The addition of ZnO onto CoZSM-5 obviously improved the yield of ethylene as well as the conversion of CO_(2).The promoting effect is attributed to the good activity of ZnO for the reverse water gas shift(RWGS)reaction,which enhances the coupling between RWGS and ethane dehydrogenation.展开更多
A series of Cr-SiO2 catalysts with a Cr content（mass fraction） ranging from 0.5% to 9% was prepared by a sol-gel method. The catalysts were characterized by XRD, N2 adsorption, EDX elemental mapping, Raman spectros-...A series of Cr-SiO2 catalysts with a Cr content（mass fraction） ranging from 0.5% to 9% was prepared by a sol-gel method. The catalysts were characterized by XRD, N2 adsorption, EDX elemental mapping, Raman spectros- copy, UV-Vis spectroscopy, XPS and H2-TPR, and their catalytic behavior in the dehydrogenation of 1-butene to 1,3-butadiene（BD） using CO2 as a soft oxidant was studied. The initial BD yield is well correlated with the amount of Cr6~ in the fresh catalysts. The highest BD yield of ca. 34% is achieved on the catalysts with 5%--9% Cr at 600 ~C -1 -1 and weight hourly space velocity（WHSV） of 4.5 g＇geat＇h ~ The promoting effect of CO2 on the BD yield was ob- served, which can be attributed to the reaction coupling between a simple dehydrogenation of 1-butene and the re- verse water-gas shift reaction as well as regaining the oxidation state（lattice oxygen） of reduced Cr3＋ species due to the mild oxidation ability of CO2. The Cr-SiO2 catalyst exhibits higher BD yield than the Cr catalyst supported on SBA-15, which is attributed to the higher amount of Cr6＋ present on the former catalyst.展开更多
A series of Sm-doped CeO_(2)/Beta composite catalysts with various Sm/Ce atomic ratios(0.1–0.4) were prepared by an incipient impregnation method, followed by calcination at 650 ℃. They were characterized by X-ray d...A series of Sm-doped CeO_(2)/Beta composite catalysts with various Sm/Ce atomic ratios(0.1–0.4) were prepared by an incipient impregnation method, followed by calcination at 650 ℃. They were characterized by X-ray diffraction(XRD), N2 adsorption, X-ray photoelectron spectroscopy(XPS), Raman, NH3-temperature programmed desorption(TPD) and CO_(2)-TPD. The incorporation of Sm into CeO_(2)/Beta increases obviously the propylene yield for the selective conversion of ethanol to propylene. The promoting effect of Sm on CeO_(2)/Beta can be attributed to two reasons. One is more acetone intermediates are generated on the Sm-doped catalysts due to the enhanced formation of oxygen vacancies. The other is the conversion of acetone intermediate to propylene is enhanced owing to weaker and fewer acid sites on the Sm-doped catalysts.展开更多
基金supported by the National Natural Science Foundation of China(No.22072027)the Fund of the Science&Technology Commission of Shanghai Municipality,China(No.19DZ2270100).
文摘Aseries of ZnO-modified cobaltous ion exchanged ZSM-5 catalysts is prepared using incipient wetness impregnation and characterized by X-ray diffraction(XRD),N2 adsorption,transmission electron microscopy(TEM),UV-Vis diffuse reflectance spectroscopy(DR UV-Vis),X-ray photoelectron spectroscopy(XPS),pyridine-adsorbed Fourier transform infrared(Py-IR)and Raman.Their catalytic performance towards CO_(2)-assisted dehydrogenation of ethane to ethylene has been evaluated.The addition of ZnO onto CoZSM-5 obviously improved the yield of ethylene as well as the conversion of CO_(2).The promoting effect is attributed to the good activity of ZnO for the reverse water gas shift(RWGS)reaction,which enhances the coupling between RWGS and ethane dehydrogenation.
基金Supported by the National Key R＆D Program of China（No.2017YFB0602200）, the National Natural Science Foundation of China（No. 91645201）, the Science and Technology Commission of Shanghai Municipality, China（No. 13DZ2275200） and the Fund of Shanghai Research Institute of Petrochemical Technology, SINOPEC, China（No. 17ZC06070001）.
文摘A series of Cr-SiO2 catalysts with a Cr content（mass fraction） ranging from 0.5% to 9% was prepared by a sol-gel method. The catalysts were characterized by XRD, N2 adsorption, EDX elemental mapping, Raman spectros- copy, UV-Vis spectroscopy, XPS and H2-TPR, and their catalytic behavior in the dehydrogenation of 1-butene to 1,3-butadiene（BD） using CO2 as a soft oxidant was studied. The initial BD yield is well correlated with the amount of Cr6~ in the fresh catalysts. The highest BD yield of ca. 34% is achieved on the catalysts with 5%--9% Cr at 600 ~C -1 -1 and weight hourly space velocity（WHSV） of 4.5 g＇geat＇h ~ The promoting effect of CO2 on the BD yield was ob- served, which can be attributed to the reaction coupling between a simple dehydrogenation of 1-butene and the re- verse water-gas shift reaction as well as regaining the oxidation state（lattice oxygen） of reduced Cr3＋ species due to the mild oxidation ability of CO2. The Cr-SiO2 catalyst exhibits higher BD yield than the Cr catalyst supported on SBA-15, which is attributed to the higher amount of Cr6＋ present on the former catalyst.
基金supported by the National Natural Science Foundation of China (Nos.22072027,91645201)the Project of the Science and Technology Commission of Shanghai Municipality,China (No.19DZ2270100)the Project of the Shanghai Research Institute of Petrochemical Technology SINOPEC (No.33750000-19-ZC0607-0005).
文摘A series of Sm-doped CeO_(2)/Beta composite catalysts with various Sm/Ce atomic ratios(0.1–0.4) were prepared by an incipient impregnation method, followed by calcination at 650 ℃. They were characterized by X-ray diffraction(XRD), N2 adsorption, X-ray photoelectron spectroscopy(XPS), Raman, NH3-temperature programmed desorption(TPD) and CO_(2)-TPD. The incorporation of Sm into CeO_(2)/Beta increases obviously the propylene yield for the selective conversion of ethanol to propylene. The promoting effect of Sm on CeO_(2)/Beta can be attributed to two reasons. One is more acetone intermediates are generated on the Sm-doped catalysts due to the enhanced formation of oxygen vacancies. The other is the conversion of acetone intermediate to propylene is enhanced owing to weaker and fewer acid sites on the Sm-doped catalysts.
