Manganese oxide was obtained by selective chemical leaching of lithium ion out from the spent LiMn2O4 electrode materials and in-situ phase transformation.The prepared manganese oxide was characterized by X-ray power ...Manganese oxide was obtained by selective chemical leaching of lithium ion out from the spent LiMn2O4 electrode materials and in-situ phase transformation.The prepared manganese oxide was characterized by X-ray power diffraction (XRD) and showed cubic λ-MnO2.The λ-MnO2 powder was found to be an effective catalyst for the synthesis of iso-amyl acetate from acetic acid and iso-amyl alcohol.The reaction results showed that when the leaching sulfuric acid concentration was 0.5 mol·L-1 and reaction time was 3 h,λ-MnO2 showed the best catalytic activity and excellent selectivity for esterification of iso-amyl acetate(yield 94.62%).展开更多
Normal spinel LiMn 2O 4 was synthesized by sol-gel method using lithium nitrate,manganese nitrate,citric acid and ethylene glycol as raw materials. LiMn 2O 4 was characterized by XRD,TG-DTA,IR,SEM and AAS.The opti...Normal spinel LiMn 2O 4 was synthesized by sol-gel method using lithium nitrate,manganese nitrate,citric acid and ethylene glycol as raw materials. LiMn 2O 4 was characterized by XRD,TG-DTA,IR,SEM and AAS.The optimum conditions for the synthesis were explored.Citric acid and ethylene glycol were mixed with molar ratio of 0.25,and the mixture was esterified at 140℃ for 4 hours.Then lithium nitrate and manganese nitrate were added with molar ratio of 0.6. In the system,the total molar of cations was equal to that of citric acid. At last, reflux the system at 105℃ for 2 hours. Dried gel was fired at 600℃ for 8 hours. Particle diameters of raw product were about 100 nm mainly. Further research shows that lithium ion of LiMn 2O 4 is easy to be extracted,and normal spinel λ-MnO 2 can be obtained after lithium ion extraction.展开更多
文摘Manganese oxide was obtained by selective chemical leaching of lithium ion out from the spent LiMn2O4 electrode materials and in-situ phase transformation.The prepared manganese oxide was characterized by X-ray power diffraction (XRD) and showed cubic λ-MnO2.The λ-MnO2 powder was found to be an effective catalyst for the synthesis of iso-amyl acetate from acetic acid and iso-amyl alcohol.The reaction results showed that when the leaching sulfuric acid concentration was 0.5 mol·L-1 and reaction time was 3 h,λ-MnO2 showed the best catalytic activity and excellent selectivity for esterification of iso-amyl acetate(yield 94.62%).
基金FundedbytheNationalNaturalScienceFoundationofChi na (No .5 9972 0 2 7)
文摘Normal spinel LiMn 2O 4 was synthesized by sol-gel method using lithium nitrate,manganese nitrate,citric acid and ethylene glycol as raw materials. LiMn 2O 4 was characterized by XRD,TG-DTA,IR,SEM and AAS.The optimum conditions for the synthesis were explored.Citric acid and ethylene glycol were mixed with molar ratio of 0.25,and the mixture was esterified at 140℃ for 4 hours.Then lithium nitrate and manganese nitrate were added with molar ratio of 0.6. In the system,the total molar of cations was equal to that of citric acid. At last, reflux the system at 105℃ for 2 hours. Dried gel was fired at 600℃ for 8 hours. Particle diameters of raw product were about 100 nm mainly. Further research shows that lithium ion of LiMn 2O 4 is easy to be extracted,and normal spinel λ-MnO 2 can be obtained after lithium ion extraction.
