摘要
At present,excessive carbon dioxide(CO_(2))emission has become an increasingly prominent global energy and environmental issue.Therefore,effective methods to convert CO_(2) into fine chemicals are urgently required.Herein,series of S-doped carbon-nitrogen(CNS-X)materials(where X denotes the ratio of thiourea and melamine substances ranging from 0.03 to 0.8)was prepared via the programmed temperature pyrolysis method,which thiourea(CH4N_(2)S)and melamine was used as the precursor of the catalysts.The sulfur source endow the CNS-X acidic sites,which cooperate synergistically with amino groups from the incomplete polymerization of melamine,leading to a bifunctional catalyst for cycloaddition reaction of CO_(2) with epoxides.These catalysts were characterized using X-ray diffraction,Fourier transform infrared spectroscopy,elemental analysis,X-ray photoelectron spectroscopy,and N_(2) adsorption-desorption techniques,confirming the successful integration of functional groups.The optimal thiourea doping concentration of 0.4 was certainly found to have considerably facilitated the efficient conversion of CO_(2) by the CNS-0.4 catalyst,in which the conversion of epichlorohydrin(ECH)could achieve over 90.0% and the selectivity of cyclic carbonate is 98.0% under 1.0 MPa at 140℃ for 10 h.The superior catalytic performance of CNS-0.4 was attributable to the synergistic effect arising from the co-existence of Lewis acidic and basic sites.Notably,using CNS-0.4 resulted in a high yield even after four reaction cycles.
基金
supported by the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515110260 and 2023A1515140049)
Special Projects in Key Areas of the Guangdong Provincial Department of Education(No.2024ZDZX2093).
