Quest for pore size effect on the catalytic property of defect-engineered MOF-808-SO4 in the addition reaction of isobutylene with ethylene glycol

In this article, a series of defect-engineered MOF-808-SO4 were prepared in which 1,3-benzenedicarboxylic acid was used as the defective ligand. All catalysts were characterized by XRD, 1H NMR, TGA-DSC, N2 sorption isotherms and acid-base titration. 1H NMR confirms the existence of H2bdc in the framework of MOF-808. With the increase of defective ligand, the pore size of MOF-808-SO4 ranges from 1.46 nm to 2.25 nm. The effect of pore size on catalytic properties of MOF-808-SO4 was investigated in the addition reaction of isobutylene with ethylene glycol. Highest conversion of ethylene glycol reaches 100% over MOF-808-20%-SO4 with the largest pore size of 2.25 nm after 8 h at 100 °C. Small pore sizes exhibited by parent MOF-808-SO4 (1.82 nm) and MOF-808-10%-SO4 (1.53 nm) give rise to high selectivity above 90% after 12 h. MOF-808-15%-SO4 with pore size of 1.99 nm shows the highest yield of target product.260