Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, ste...Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.展开更多
Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene(TCE).In this work,the liquid-phase hydrogenation of TCE by Raney Ni(R-Ni)and Pd/C under an open syste...Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene(TCE).In this work,the liquid-phase hydrogenation of TCE by Raney Ni(R-Ni)and Pd/C under an open system have been studied,in which nascent H_(2)(Nas-H_(2))generated in situ from the cathode acted as a hydrogen source.Experimental results showed that TCE was completely eliminate from the solution through the synergistic effects of hydrodechlorination and air flotation due to the formation of continuous micro/nano-sized Nas-H_(2)bubbles from the cathode.Furthermore,the effects of inorganic anions and organic solvents on R-Ni and Pd/C hydrogenation activity were investigated,respectively.The results showed that NO_(3)^(-) and acetonitrile can form a competitive reaction with TCE;Sulfur with lone-pair electrons will cause irreversible poisoning to these two catalysts,and have a stronger inhibitory effect on Pd/C.This work helps to realize the separation of volatile halogenated compounds from water environment and provides certain data support for the choice of catalyst in the actual liquid-phase hydrogenation system.展开更多
To study the formation of detrimental phases under the sulfur gas impurity to the long-term degradation in the cathode material,the classic cathode material,(La_(0.8)Sr_(0.2))_(0.95)MnO_(3)(LSM),was prepared,sintered,...To study the formation of detrimental phases under the sulfur gas impurity to the long-term degradation in the cathode material,the classic cathode material,(La_(0.8)Sr_(0.2))_(0.95)MnO_(3)(LSM),was prepared,sintered,and annealed at 800,900,and 1000℃ in the sulfur-containing atmospheres,respectively.Through X-ray diffraction,scanning electron microscope,and transmission electron microscopy techniques,as well as the computer coupling of phase diagrams and thermochemistry methodology,the secondary phases,especially the detrimental ones,under different conditions were predicted and experimentally verified correspondingly.Furthermore,sulfur poisoning results indicate that the accelerated tests might have degradation mechanisms different from actual operation conditions.More importantly,comprehensive comparisons among various impurity-containing conditions were also made to recommend better operation parameters.展开更多
基金Project(2009CK2001) supported by the Science & Technology Development Key Program of Hunan Province STA of ChinaProject supported by the Young Teachers Program of Hunan University,China
文摘Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.
基金supported by the National Natural Science Foundation of China(No.51878169)the Guangdong Innovation Team Project for Colleges and Universities(No.2016KCXTD023)+1 种基金Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2017)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515110497)。
文摘Hydrodechlorination is a promising technology for the remediation of water body contaminated with trichloroethylene(TCE).In this work,the liquid-phase hydrogenation of TCE by Raney Ni(R-Ni)and Pd/C under an open system have been studied,in which nascent H_(2)(Nas-H_(2))generated in situ from the cathode acted as a hydrogen source.Experimental results showed that TCE was completely eliminate from the solution through the synergistic effects of hydrodechlorination and air flotation due to the formation of continuous micro/nano-sized Nas-H_(2)bubbles from the cathode.Furthermore,the effects of inorganic anions and organic solvents on R-Ni and Pd/C hydrogenation activity were investigated,respectively.The results showed that NO_(3)^(-) and acetonitrile can form a competitive reaction with TCE;Sulfur with lone-pair electrons will cause irreversible poisoning to these two catalysts,and have a stronger inhibitory effect on Pd/C.This work helps to realize the separation of volatile halogenated compounds from water environment and provides certain data support for the choice of catalyst in the actual liquid-phase hydrogenation system.
文摘To study the formation of detrimental phases under the sulfur gas impurity to the long-term degradation in the cathode material,the classic cathode material,(La_(0.8)Sr_(0.2))_(0.95)MnO_(3)(LSM),was prepared,sintered,and annealed at 800,900,and 1000℃ in the sulfur-containing atmospheres,respectively.Through X-ray diffraction,scanning electron microscope,and transmission electron microscopy techniques,as well as the computer coupling of phase diagrams and thermochemistry methodology,the secondary phases,especially the detrimental ones,under different conditions were predicted and experimentally verified correspondingly.Furthermore,sulfur poisoning results indicate that the accelerated tests might have degradation mechanisms different from actual operation conditions.More importantly,comprehensive comparisons among various impurity-containing conditions were also made to recommend better operation parameters.
