La_(1-x)CoO_(3-δ)catalysts with different non-stoichiometry of lanthanum ions were synthesized by using the sol-gel method,and their catalytic performance in toluene combustion was investigated.The results showed tha...La_(1-x)CoO_(3-δ)catalysts with different non-stoichiometry of lanthanum ions were synthesized by using the sol-gel method,and their catalytic performance in toluene combustion was investigated.The results showed that the catalytic activity and stability of A-site nonstoichiometric La_(1-x)CoO_(3-δ)were improved to a certain extent compared with pure LaCoO_(3)perovskite.Among them,the La_(0.9)CoO_(3-δ)catalyst gave the best catalytic performance for toluene oxidation.It achieved 90%toluene conversion at 205℃under the conditions of a WHSV(weight hourly space velocity)of 22,500 mL/(g·hr)and a 500 ppmV-toluene concentration.Various characterization techniques were used to investigate the relationship between the structure of these catalysts and their catalytic performance.It was found that the non-stoichiometric modification of the lanthanum ion at position A in LaCoO_(3)changed the surface element state of the catalyst and increased the oxygen vacancy content,thus,combined with improved reducibility,improving toluene degradation on the catalyst.展开更多
Herein,Na^(+)and Ca^(2+)are introduced to MnO_(2)through cation-exchange method.The presence of Na^(+)and Ca^(2+)significantly enhance the catalytic activity of MnO_(2)in toluene oxidation.Among them,the Ca-MnO_(2)cat...Herein,Na^(+)and Ca^(2+)are introduced to MnO_(2)through cation-exchange method.The presence of Na^(+)and Ca^(2+)significantly enhance the catalytic activity of MnO_(2)in toluene oxidation.Among them,the Ca-MnO_(2)catalyst exhibits the best catalytic activity(T_(50)=194℃,T_(90)=215℃,E_a=57.2 k J/mol,reaction rate 8.40×10^(-10)mol/(sec·m^(2))at 210℃.T_(50)and T_(90):the temperature of 50%and 90%toluene conversion;E a:apparent activation energy)and possess high tolerance against 2.0 vol.%water vapor.Results reveal that the increased acidic sites of the MnO_(2)sample can enhance the adsorption of gaseous toluene,and the mobility of oxygen species and the content of reactive oxygen species in the catalyst are significantly improved due to the formed oxygen vacancy.Thus these two factors result in excellent catalytic performance for toluene oxidation combining with the weak CO_(2)adsorption ability.展开更多
Porous liquids,an emerging type of flowing liquid materials,are composed of porous solids and polymer chains/sterically hindered sol-vents,combining the advantages of porous solids'permanent porosity and liquid...Porous liquids,an emerging type of flowing liquid materials,are composed of porous solids and polymer chains/sterically hindered sol-vents,combining the advantages of porous solids'permanent porosity and liquid's fluidity.Therefore,porous liquids have shown enormous potentials in many applications.However,these applications are limited to gas adsorption[1],transport[2]and separation[3],which is unfa-vorable for the development of porous liquids.Therefore,expanding the application of porous liquids in other fields is quite meaningful.展开更多
基金support from National Key Research and Development Program of China(No.2019YFC1903903)the National Natural Science Foundation of China(No.21876019)+1 种基金Fundamental Research Funds for the Central Universities(No.DUT20RC(4)003)Natural Science Foundation of Liaoning Province(No.2020-BS-056).
文摘La_(1-x)CoO_(3-δ)catalysts with different non-stoichiometry of lanthanum ions were synthesized by using the sol-gel method,and their catalytic performance in toluene combustion was investigated.The results showed that the catalytic activity and stability of A-site nonstoichiometric La_(1-x)CoO_(3-δ)were improved to a certain extent compared with pure LaCoO_(3)perovskite.Among them,the La_(0.9)CoO_(3-δ)catalyst gave the best catalytic performance for toluene oxidation.It achieved 90%toluene conversion at 205℃under the conditions of a WHSV(weight hourly space velocity)of 22,500 mL/(g·hr)and a 500 ppmV-toluene concentration.Various characterization techniques were used to investigate the relationship between the structure of these catalysts and their catalytic performance.It was found that the non-stoichiometric modification of the lanthanum ion at position A in LaCoO_(3)changed the surface element state of the catalyst and increased the oxygen vacancy content,thus,combined with improved reducibility,improving toluene degradation on the catalyst.
基金financially supported by the National Natural Science Foundation of China(No.21876019 and 21806017)National Key Research and Development Program of China(No.2019YFC1903903)+1 种基金Fundamental Research Funds for the Central Universities(No.DUT19LAB10)Dalian Science and Technology Innovation Fund(No.2019J12SN74).
文摘Herein,Na^(+)and Ca^(2+)are introduced to MnO_(2)through cation-exchange method.The presence of Na^(+)and Ca^(2+)significantly enhance the catalytic activity of MnO_(2)in toluene oxidation.Among them,the Ca-MnO_(2)catalyst exhibits the best catalytic activity(T_(50)=194℃,T_(90)=215℃,E_a=57.2 k J/mol,reaction rate 8.40×10^(-10)mol/(sec·m^(2))at 210℃.T_(50)and T_(90):the temperature of 50%and 90%toluene conversion;E a:apparent activation energy)and possess high tolerance against 2.0 vol.%water vapor.Results reveal that the increased acidic sites of the MnO_(2)sample can enhance the adsorption of gaseous toluene,and the mobility of oxygen species and the content of reactive oxygen species in the catalyst are significantly improved due to the formed oxygen vacancy.Thus these two factors result in excellent catalytic performance for toluene oxidation combining with the weak CO_(2)adsorption ability.
基金supported by the National Natural Science Foundation of China(22278190)China Postdoctoral Science Foundation(2022M711382)Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment.
文摘Porous liquids,an emerging type of flowing liquid materials,are composed of porous solids and polymer chains/sterically hindered sol-vents,combining the advantages of porous solids'permanent porosity and liquid's fluidity.Therefore,porous liquids have shown enormous potentials in many applications.However,these applications are limited to gas adsorption[1],transport[2]and separation[3],which is unfa-vorable for the development of porous liquids.Therefore,expanding the application of porous liquids in other fields is quite meaningful.
