Cu ₃(BTC) ₂ (BTC = 1,3,5-benzene tricarboxylate) was synthesized from cooled reagents in ethanol-water solvent mixtures and in ethanol solvent at room temperature involving quenching at -196 °C and freeze drying in order to limit crystal growth. These approaches are handy to synthesize this MOF with narrow particle size distribution in the range of 100 nm to 5 microns and to achieve excellent crystallinity and unprecedented porosity. The nano-version of Cu ₃(BTC) ₂ outperforms micron size crystals in catalyzing methanolysis of styrene oxide.