Pristine ETS-10 and AM-6 and their Co2+-exchanged forms were prepared, and their catalytic activities toward the oxidation of styrene in oxygen atmosphere were studied in dimethylformamide. The catalysts were denoted ...Pristine ETS-10 and AM-6 and their Co2+-exchanged forms were prepared, and their catalytic activities toward the oxidation of styrene in oxygen atmosphere were studied in dimethylformamide. The catalysts were denoted as Co-E10-n(n = 0, 9, 26, 68, 81) and Co-A6-m(m = 0, 8, 23, 63, 79), where n and m denote the degree of Co2+ exchange. The products of the oxidation process were identified as styrene epoxide(E) and benzaldehyde(B). Both the pristine forms, ETS-10(Co-E10-0) and AM-6(Co-A6-0), and Co2+-exchanged forms displayed catalytic activities. With increasing n or m, the conversion, and hence the rate, increased. Specifically, the rates varied from 6.1 to 12.5 mmol·g-1·h-1with increasing n(Co-E10-n catalysts) and from 5.4 to 12.4 mmol·g-1·h-1 with increasing m(Co-A6-m catalysts). In contrast, the E/B ratio decreased with increasing n or m. More specifically,the E/B ratio decreased from 2.1 to 0.1 with increasing n from 0 to 81(Co-E10-n catalysts) and from 1.3 to 0.1 with increasing m from 0 to 79(Co-A6-m catalysts). Co-E10-9 displayed the highest E yield and Co-A6-79 generated the highest B yield. The highest turnover frequency obtained was 36.3 Co-1·h-1, which was the highest one obtained among those obtained for the Co2+-exchanged zeolites and mesoporous silica reference materials studied in this work.展开更多
基金supported by the Ministry of Science,ICT and Future Planning through the National Research Foundation of Korea(no.2009-0093886,no.2012R1A2A3A01009806)
文摘Pristine ETS-10 and AM-6 and their Co2+-exchanged forms were prepared, and their catalytic activities toward the oxidation of styrene in oxygen atmosphere were studied in dimethylformamide. The catalysts were denoted as Co-E10-n(n = 0, 9, 26, 68, 81) and Co-A6-m(m = 0, 8, 23, 63, 79), where n and m denote the degree of Co2+ exchange. The products of the oxidation process were identified as styrene epoxide(E) and benzaldehyde(B). Both the pristine forms, ETS-10(Co-E10-0) and AM-6(Co-A6-0), and Co2+-exchanged forms displayed catalytic activities. With increasing n or m, the conversion, and hence the rate, increased. Specifically, the rates varied from 6.1 to 12.5 mmol·g-1·h-1with increasing n(Co-E10-n catalysts) and from 5.4 to 12.4 mmol·g-1·h-1 with increasing m(Co-A6-m catalysts). In contrast, the E/B ratio decreased with increasing n or m. More specifically,the E/B ratio decreased from 2.1 to 0.1 with increasing n from 0 to 81(Co-E10-n catalysts) and from 1.3 to 0.1 with increasing m from 0 to 79(Co-A6-m catalysts). Co-E10-9 displayed the highest E yield and Co-A6-79 generated the highest B yield. The highest turnover frequency obtained was 36.3 Co-1·h-1, which was the highest one obtained among those obtained for the Co2+-exchanged zeolites and mesoporous silica reference materials studied in this work.
