In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of ...In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of NO using NH<sub>3</sub>. We investigated the effects of Fe/Ce molar ratio, the gas hourly space velocity (GHSV), the stability and SO<sub>2</sub>/H<sub>2</sub>O resistance of the catalysts. The results showed that the FeCe(1:6)O<sub> x </sub> (Ce/Fe molar ratio is 1:6) catalyst, which has some ordered parallel channels, exhibited good SCR performance. The FeCe(1:6)O<sub> x </sub> catalyst had the highest NO conversion with an activity of 94-99% at temperatures between 200 and 300 °C at a space velocity of 28,800 h<sup>−1</sup>. The NO conversion for the FeCe(1:6)O<sub> x </sub> catalyst also reached 80-98% between 200 and 300 °C at a space velocity of 204,000 h<sup>−1</sup>. In addition, the FeCe(1:6)O<sub> x </sub> catalyst demonstrated good stability in a 10-h SCR reaction at 200-300 °C. Even in the presence of SO<sub>2</sub> and H<sub>2</sub>O, the FeCe(1:6)O<sub> x </sub> catalyst exhibited good SCR performance.展开更多
Te reason that the stoichiometry of gas to water in artifcial gas hydrates formed on porous materials is much higher than that in nature is still ambiguous.Fortunately,based on our experimental thermodynamic and kinet...Te reason that the stoichiometry of gas to water in artifcial gas hydrates formed on porous materials is much higher than that in nature is still ambiguous.Fortunately,based on our experimental thermodynamic and kinetic study on the gas hydrate formation behavior with classic ordered mesoporous carbon CMK-3 and irregular porous activated carbon combined with density functional theory calculations,we discover a microscopic pathway of the gas hydrate formation on porous materials.Two interesting processes including(I)the replacement of water adsorbed on the carbon surface by gas and(II)further replacement of water in the pore by gas accompanied with the gas condensation in the pore and growth of gas hydrate crystals out of the pore were deduced.As a result,a great enhancement of the selectivity and regeneration for gas separation was achieved by controlling the gas hydrate formation behavior accurately.展开更多
基金supported by the National Natural Science Foundation of China (No.21206108)Tianjin Municipal Science and Technology Commission (No.14JCYBJC21200)
文摘In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of NO using NH<sub>3</sub>. We investigated the effects of Fe/Ce molar ratio, the gas hourly space velocity (GHSV), the stability and SO<sub>2</sub>/H<sub>2</sub>O resistance of the catalysts. The results showed that the FeCe(1:6)O<sub> x </sub> (Ce/Fe molar ratio is 1:6) catalyst, which has some ordered parallel channels, exhibited good SCR performance. The FeCe(1:6)O<sub> x </sub> catalyst had the highest NO conversion with an activity of 94-99% at temperatures between 200 and 300 °C at a space velocity of 28,800 h<sup>−1</sup>. The NO conversion for the FeCe(1:6)O<sub> x </sub> catalyst also reached 80-98% between 200 and 300 °C at a space velocity of 204,000 h<sup>−1</sup>. In addition, the FeCe(1:6)O<sub> x </sub> catalyst demonstrated good stability in a 10-h SCR reaction at 200-300 °C. Even in the presence of SO<sub>2</sub> and H<sub>2</sub>O, the FeCe(1:6)O<sub> x </sub> catalyst exhibited good SCR performance.
基金Ruqiang Zou acknowledges the funding support from the National Natural Science Foundation of China(Grant 51772008)Yanli Zhao is thankful for the support by the Singapore Academic Research Fund(Grants RG5/16,RG11/17,and RG114/17)the Singapore Agency for Science,Technology and Research(A∗STAR)AME IRG grant(Grant A1783c0007).
文摘Te reason that the stoichiometry of gas to water in artifcial gas hydrates formed on porous materials is much higher than that in nature is still ambiguous.Fortunately,based on our experimental thermodynamic and kinetic study on the gas hydrate formation behavior with classic ordered mesoporous carbon CMK-3 and irregular porous activated carbon combined with density functional theory calculations,we discover a microscopic pathway of the gas hydrate formation on porous materials.Two interesting processes including(I)the replacement of water adsorbed on the carbon surface by gas and(II)further replacement of water in the pore by gas accompanied with the gas condensation in the pore and growth of gas hydrate crystals out of the pore were deduced.As a result,a great enhancement of the selectivity and regeneration for gas separation was achieved by controlling the gas hydrate formation behavior accurately.
