Exploring the Possibility of Strong Basic Sites Fabrication on ZIF-67 at Low Temperature

Solid strong base catalysts have attracted much attention for their excellent catalytic performance and environmental friendliness due to their heterogeneous properties. However, such kinds of catalyst usually need higher temperature to be activated. Therefore, it is still a challenge to obtain high activity catalyst at lower fabrication temperature. In this paper, zeolitic imidazolate framework-67 (ZIF-67) was prepared. Through the redox reaction between the Co2+ and KNO3, the strong basic sites can be produced at lower temperature on it. Thermogravimetry-mass spectrometer result showed that the base precursor began to be transformed into basic sites at about 335 °C. The solid base catalyst was used for transesterification of ethylene carbonate and methanol. The yield of dimethyl carbonate was up to 59% under the temperature of 70 °C, reaction time of 4 h, and catalyst amount of 0.05 g, which showing good catalytic activity.