Main observation and conclusion A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron(B_(2)cat_(2))as the boron source is introduced.The borylati...Main observation and conclusion A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron(B_(2)cat_(2))as the boron source is introduced.The borylation reaction is operationally simple and shows high functional group tolerance and broad substrate scope.Preliminary mechanistic studies suggest that the reaction proceeds through S_(N)2-based radical-generation strategy.展开更多
As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people＇s attention. Catalytic ozonation technology, which involves production of ·OH rad...As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people＇s attention. Catalytic ozonation technology, which involves production of ·OH radical with strong oxidation ability, is widely used in the treatment of organic-containing wastewater. In this work, MgO-Co3O4 composite metal oxide catalysts prepared with different fabrication conditions have been systematically evaluated and compared in the catalytic ozonation of ammonia（50 mg/L） in water. In terms of high catalytic activity in ammonia decomposition and high selectivity for gaseous nitrogen, the catalyst with MgO-Co3O4 molar ratio 8：2, calcined at 500°C for 3 hr, was the best one among the catalysts we tested, with an ammonia nitrogen removal rate of 85.2% and gaseous nitrogen selectivity of44.8%. In addition, the reaction mechanism of ozonation oxidative decomposition of ammonia nitrogen in water with the metal oxide catalysts was discussed. Moreover, the effect of coexisting anions on the degradation of ammonia was studied, finding that SO2-4 and HCO-3 could inhibit the catalytic activity while CO2-3 and Br-could promote it. The presence of coexisting cations had very little effect on the catalytic ozonation of ammonia nitrogen. After five successive reuses, the catalyst remained stable in the catalytic ozonation of ammonia.展开更多
基金Financial support from the National Natural Science Foundation of China(Nos.21772046,2193103,22001038)are gratefully acknowledged.
文摘Main observation and conclusion A method for photoinduced NaI-promoted radical borylation of aliphatic halides and pseudohalides with bis(catecholato)diboron(B_(2)cat_(2))as the boron source is introduced.The borylation reaction is operationally simple and shows high functional group tolerance and broad substrate scope.Preliminary mechanistic studies suggest that the reaction proceeds through S_(N)2-based radical-generation strategy.
基金supported the National Natural Science Foundation of China (Nos. 51164014 and 51568023)
文摘As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people＇s attention. Catalytic ozonation technology, which involves production of ·OH radical with strong oxidation ability, is widely used in the treatment of organic-containing wastewater. In this work, MgO-Co3O4 composite metal oxide catalysts prepared with different fabrication conditions have been systematically evaluated and compared in the catalytic ozonation of ammonia（50 mg/L） in water. In terms of high catalytic activity in ammonia decomposition and high selectivity for gaseous nitrogen, the catalyst with MgO-Co3O4 molar ratio 8：2, calcined at 500°C for 3 hr, was the best one among the catalysts we tested, with an ammonia nitrogen removal rate of 85.2% and gaseous nitrogen selectivity of44.8%. In addition, the reaction mechanism of ozonation oxidative decomposition of ammonia nitrogen in water with the metal oxide catalysts was discussed. Moreover, the effect of coexisting anions on the degradation of ammonia was studied, finding that SO2-4 and HCO-3 could inhibit the catalytic activity while CO2-3 and Br-could promote it. The presence of coexisting cations had very little effect on the catalytic ozonation of ammonia nitrogen. After five successive reuses, the catalyst remained stable in the catalytic ozonation of ammonia.
