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
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.
