Journal of Catalysis, Vol.370, 38-45, 2019
Robust and efficient catalyst derived from bimetallic Zn/Co zeolitic imidazolate frameworks for CO2 conversion
A robust catalyst generated from the pyrolysis of bimetallic Zn/Co-ZIF comprising magnetic properties demonstrated to be an effective heterogeneous catalyst system for CO2 conversion reaction without the need of co-catalyst and solvent. Controllable pyrolysis under various conditions resulted in a unique active structure composed of metallic particles stabilized in a nitrogen-doped carbon matrix. The metallic particles acting as acid sites are dispersed in a nitrogen-doped porous carbon-wall which provides the basic sites. These sites are created during the pyrolysis process of Zn/Co-ZIF used as a special template under a controlled atmosphere. The resulting material possessing both, acid and basic sites, showed an excellent catalytic performance for the cycloaddition of CO2 into epoxides as these sites correspond to the active sites in the catalytic cycle. Additional, the pyrolysis conditions indicated to play an important role in the properties of the resulting materials and in parallel with the catalytic performance. The catalytic material proved to be very robust and maintained high activities for at least eleven cycles using the optimized reaction condition. Moreover, the magnetic property of the resulting catalyst is advantageous especially for the separation from the reaction mixture. (C) 2018 Elsevier Inc. All rights reserved.