At present, all hydrogen storage alloys are poisoned by hydrogen mixed with CO, CO2, etc, which decreases the hydrogen storage property sharply. Zr-Co based hydrogen storage alloys with good poisoning resistance were ...At present, all hydrogen storage alloys are poisoned by hydrogen mixed with CO, CO2, etc, which decreases the hydrogen storage property sharply. Zr-Co based hydrogen storage alloys with good poisoning resistance were prepared by alloying, fluorinating, and electroless plating. The experiment results show that the poisoning resistance of the Zr-Co based alloy was improved remarkably after the treatments. The poisoning resistance mechanism of the Zr-Co based hydrogen storage alloys was analyzed.展开更多
A new type of catalytic material for purification of automobile exhaust, Cu Mn Ce O/ γ Al 2O 3, has been studied. The factors affecting its catalytic activity, such as calcination temperature and the period of calcin...A new type of catalytic material for purification of automobile exhaust, Cu Mn Ce O/ γ Al 2O 3, has been studied. The factors affecting its catalytic activity, such as calcination temperature and the period of calcinations and so on have been investigated. Its catalytic activity after SO 2 poisoning was determined in a fixed bed reactor by exposing the sample to the atmosphere of 160?mL/min SO 2/air. The study reveals that the catalyst has shown high catalytic activities for the conversion of NH 3 oxidation by NO after sulfate. The conversion of NO reduction over the sulfated catalyst is somewhat higher than that over the fresh catalyst except that the optimum temperature has increased about 100?℃. Also at the optimum process for the experiment, the selective catalytic oxidation of CO by NO is over 76% and the conversion of NO reduction is over 80% by NH 3.展开更多
Improving the alkali resistance of catalysts for selective catalytic reduction of NO_(x) with NH_(3) is still a challenge.In this work,the co-modification with Fe,Ce and sulfates on V_(2)O_(5)-WO_(3)/TiO_(2) catalysts...Improving the alkali resistance of catalysts for selective catalytic reduction of NO_(x) with NH_(3) is still a challenge.In this work,the co-modification with Fe,Ce and sulfates on V_(2)O_(5)-WO_(3)/TiO_(2) catalysts(denoted as xSFeCeVWTi) significantly enhances its alkali resistance with K element as a representative.A series of xSFeCeVWTi catalysts was synthesized by wet impregnation with designed 0.05Fe/V, 1.5Ce/V and different S/V molar ratios x.The NO_(x) conversion and K resistance of xSFeCeVWTi catalysts increase with the increase of loading amounts of sulfates but no longer further increase as the sulfates load is excessive to block the pores of catalysts and hinder the adsorption of reactants.The optimal modified catalyst in about 2.2S/V actual loading ratio,corresponding to 10.5SFeCeVWTi sample,shows over 99.0%NO_(x) conversion and N_(2) selectivity at 300-400℃ after K-poisoning.The interaction between Fe,Ce and V improves its redox ability but slightly weakens surface acidity,while the proper amount of sulfate species enriches surface Br?nsted acid sites but attenuates its redox capability.However,a balance of redox capacity and surface acidity,caused by Fe,Ce and sulfate co-modification,contributes to the excellent K resistance of 10.5SFeCeVWTi catalyst.Finally,the change of physicochemical properties influences the reaction mechanism which follows the Eley-Rideal mechanism on 10.SSFeCeVWTi catalyst.These results show that the co-modification with Fe,Ce and sulfates is a good way to improve the alkali tolerance of V_(2)O_(5)-WO_(3)/TiO_(2) catalyst in industrial applications.展开更多
文摘At present, all hydrogen storage alloys are poisoned by hydrogen mixed with CO, CO2, etc, which decreases the hydrogen storage property sharply. Zr-Co based hydrogen storage alloys with good poisoning resistance were prepared by alloying, fluorinating, and electroless plating. The experiment results show that the poisoning resistance of the Zr-Co based alloy was improved remarkably after the treatments. The poisoning resistance mechanism of the Zr-Co based hydrogen storage alloys was analyzed.
文摘A new type of catalytic material for purification of automobile exhaust, Cu Mn Ce O/ γ Al 2O 3, has been studied. The factors affecting its catalytic activity, such as calcination temperature and the period of calcinations and so on have been investigated. Its catalytic activity after SO 2 poisoning was determined in a fixed bed reactor by exposing the sample to the atmosphere of 160?mL/min SO 2/air. The study reveals that the catalyst has shown high catalytic activities for the conversion of NH 3 oxidation by NO after sulfate. The conversion of NO reduction over the sulfated catalyst is somewhat higher than that over the fresh catalyst except that the optimum temperature has increased about 100?℃. Also at the optimum process for the experiment, the selective catalytic oxidation of CO by NO is over 76% and the conversion of NO reduction is over 80% by NH 3.
基金Project supported by Fujian Provincial Department of Science and Technology,China (2020Y0085)Youth Innovation Promotion Association,Chinese Academy of Sciences (2020309)the Cultivating Project of Strategic Priority Research Program of Chinese Academy of Sciences (XDPB1902)。
文摘Improving the alkali resistance of catalysts for selective catalytic reduction of NO_(x) with NH_(3) is still a challenge.In this work,the co-modification with Fe,Ce and sulfates on V_(2)O_(5)-WO_(3)/TiO_(2) catalysts(denoted as xSFeCeVWTi) significantly enhances its alkali resistance with K element as a representative.A series of xSFeCeVWTi catalysts was synthesized by wet impregnation with designed 0.05Fe/V, 1.5Ce/V and different S/V molar ratios x.The NO_(x) conversion and K resistance of xSFeCeVWTi catalysts increase with the increase of loading amounts of sulfates but no longer further increase as the sulfates load is excessive to block the pores of catalysts and hinder the adsorption of reactants.The optimal modified catalyst in about 2.2S/V actual loading ratio,corresponding to 10.5SFeCeVWTi sample,shows over 99.0%NO_(x) conversion and N_(2) selectivity at 300-400℃ after K-poisoning.The interaction between Fe,Ce and V improves its redox ability but slightly weakens surface acidity,while the proper amount of sulfate species enriches surface Br?nsted acid sites but attenuates its redox capability.However,a balance of redox capacity and surface acidity,caused by Fe,Ce and sulfate co-modification,contributes to the excellent K resistance of 10.5SFeCeVWTi catalyst.Finally,the change of physicochemical properties influences the reaction mechanism which follows the Eley-Rideal mechanism on 10.SSFeCeVWTi catalyst.These results show that the co-modification with Fe,Ce and sulfates is a good way to improve the alkali tolerance of V_(2)O_(5)-WO_(3)/TiO_(2) catalyst in industrial applications.
