Conversion of CO2 into cyclic carbonates by a Co(ii) metal-organic framework and the improvement of catalytic activity via nanocrystallizationElectronic supplementary information (ESI) available: Materials and methods, synthesis of catalysts, experimental procedures and characterization data (1H and 13C NMR spectra) for products, and the conceivable reaction mechanism. See DOI: 10.1039/c7dt04882c

• Main Authors: Ji, Xiao-He, Zhu, Ning-Ning, Ma, Jian-Gong, Cheng, Peng
• Format: Journal Article
• Language: English
• Published: 06.02.2018
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt04882c

The Co( ii ) metal-organic framework (MOF) {[Co(μ 3 -L)(H 2 O)]·0.5H 2 O} n ( 1 , H 2 L = thiazolidine 2,4-dicarboxylic acid) with rich Lewis acid sites was used as a catalyst for the conversion of CO 2 and propylene oxide into propylene carbonate with a yield of up to 98% under 50 °C and 1 atm. 1 exhibited excellent reusability, which could be regenerated easily for at least five runs without a decrease in the yield. Importantly, we synthesized two types of nano-crystals ( N1 and N2 ) of 1 with polyvinylpyrrolidone (PVP) and hexadecyltrimethylammonium bromide (CTAB) as surfactants, respectively, and investigated their catalytic properties in comparison with that of 1 in the powder phase. A significant enhancement in both catalytic efficiency and product yield was observed when 1 was nano-crystallized. This is the first investigation about the relationship between the morphology and the catalytic parameters of MOFs. The results showed a strategy for efficiently applying MOFs as catalysts towards CO 2 conversion, which could also be used in other MOF-catalyzed processes. Nanocrystallization of MOFs provides a strategy for efficiently applying MOFs as catalysts towards CO 2 conversion and other MOF-catalyzed processes.