Catalytic Performance of Zr-Based Metal-Organic Frameworks Zr-abtc and MIP-200 in Selective Oxidations with H 2 O 2

• Published in: Chemistry : a European journal Vol. 27; no. 23; pp. 6985 - 6992
• Main Authors: Maksimchuk, Nataliya V, Ivanchikova, Irina D, Cho, Kyung Ho, Zalomaeva, Olga V, Evtushok, Vasiliy Yu, Larionov, Kirill P, Glazneva, Tatiana S, Chang, Jong-San, Kholdeeva, Oxana A
• Format: Journal Article
• Language: English
• Published: Germany 21.04.2021
• Subjects: Zr; alpha,beta-unsaturated ketones; epoxidation; hydrogen peroxide; metal-organic frameworks
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202005152

The catalytic performance of Zr-abtc and MIP-200 metal-organic frameworks consisting of 8-connected Zr clusters and tetratopic linkers was investigated in H O -based selective oxidations and compared with that of 12-coordinated UiO-66 and UiO-67. Zr-abtc demonstrated advantages in both substrate conversion and product selectivity for epoxidation of electron-deficient C=C bonds in α,β-unsaturated ketones. The significant predominance of 1,2-epoxide in carvone epoxidation, coupled with high sulfone selectivity in thioether oxidation, points to a nucleophilic oxidation mechanism over Zr-abtc. The superior catalytic performance in the epoxidation of unsaturated ketones correlates with a larger amount of weak basic sites in Zr-abtc. Electrophilic activation of H O can also be realized, as evidenced by the high activity of Zr-abtc in epoxidation of the electron-rich C=C bond in caryophyllene. XRD and FTIR studies confirmed the retention of the Zr-abtc structure after the catalysis. The low activity of MIP-200 in H O -based oxidations is most likely related to its specific hydrophilicity, which disfavors adsorption of organic substrates and H O .