“Open” sites on the nodes of UiO-66 are converted to catalytically active Zr-OOH and can coordinate with solvent/products.

Three HO3S-functionalized porous organic polymers (HO3S-POPs) with high surface areas (500–700 m2/g) and a broad range of porosity profiles were synthesized and tested against homogeneous-acid analogs and commercially available acid resins to evaluate their relative catalytic activities in the acid-catalyzed conversion of fructose to HMF. Comparison of fructose conversions and HMF yields demonstrates that the sulfonated POPs with hierarchical porosity can achieve catalytic activities that rival those of their homogeneous counterparts. The associated HMF selectivities represent optimized values that increase with higher temperature and faster heating, both of which can reduce the reaction time and limit product decomposition. Due to their intrinsically high mesoporosity and number of accessible acid sites, these HO3S-POPs also outperform the commercially available Amberlyst 15 resin catalyst and its crushed variant.

A molecular catalyst, (sal)Mo VI , and a heterogeneous catalyst, either Pd or Au nanoparticles (NPs), were integrated into one UiO-66 MOF microcrystal. The resulting dually functionalized catalysts, Pd@UiO-66-(sal)Mo and Au/UiO-66-(sal)Mo, have been utilized for a one-pot tandem reaction of H 2 O 2 generation and selective liquid-phase alkene oxidation. The NPs serve as catalysts for the production of H 2 O 2 from H 2 and O 2 gases, while the (sal)Mo moieties function as the oxidation catalyst. When the metal NPs are fully encapsulated within the MOF microcrystals, the alkene hydrogenation side reaction is largely suppressed, with a 6-fold decrease in the hydrogenation/oxidation product ratio for 5-bromo-1-cyclooctene favoring the epoxide as the major product. For Au/UiO-66-(sal)Mo, where the two catalysts are in close proximity on the MOF microcrystal, the enhancement in oxidation productivity is increased by 10 times in comparison to the [Au/UiO-66-NH 2 + UiO-66-sal(Mo)] physical mixture of the two singly functionalized MOFs.