《Table 3 Aerobic oxidation of HMF to DFF under diff erent amounts of keto-ABNO and NaNO 2》

  提示：宽带有限、当前游客访问压缩模式

本系列图表出处文件名：随高清版一同展现

《"High-Efficiency Preparation of 2,5-Diformylfuran with a Keto-ABNO Catalyst Under Mild Conditions"》

1. 获取 高清版本忘记账户？点击这里登录

1. 下载图表忘记账户？点击这里登录

Reaction conditions:HMF（65 mg，0.5 mmol），acetic acid（4 mL），Na NO 2，keto-ABNO，O 2（10 mL/min），40°C，2 h

It is known that the dosage of the catalyst will have a signifi cant infl uence on a reaction.An insuffi cient amount of catalyst will lead to low catalytic effi ciency，which is mainly manifested as a low conversion rate.However，an excessiveamount of a catalyst leads to an excessive reaction and increases production costs.We investigated the infl uence of the amounts of catalyst and co-catalyst on the oxidation of HMF to DFF，and the results are shown in Table 3.We found both keto-ABNO and NaNO 2 to play crucial roles in the conversion of HMF to DFF.An experiment was also conducted without using keto-ABNO and NaNO 2，for which no DFF could be detected（Table 3，entry 1）.In the absence of keto-ABNO，only a HMF conversion of 69.4%was achieved，and no DFF could be detected（Table 3，entry 2）.In the presence of keto-ABNO without NaNO 2，a full conversion of HMF was achieved，but the selectivity to DFF was relatively low（Table 3，entry 6）.These results indicate that the highly selective oxidation of HMF to DFF requires a synergic catalytic eff ect between keto-ABNO and the co-catalyst NaNO 2.Moreover，the insuffi cient use of keto-ABNO results in the partial conversion of HMF to DFF.Increasing the amounts of keto-ABNO and NaNO 2 does not lead to a continuousincrease in the DFF yield.Considering the formation of other by-products（e.g.，FFCA，FDCA），the optimal dosages of keto-ABNO and NaNO 2 are 2 mg and 3.4 mg，respectively.We note that the dosages of catalysts used in our catalytic system are much lower than those reported in Refs.[2，22]，while the amount of catalyst used represents a major cost in the industrial production of DFF.The high catalytic effi ciency of keto-ABNO and NaNO 2 makes them good candidates for the industrial-scale production of DFF.