Size-controllable synthesis of uniform submicron Sn-Beta from tailorable seeds

Crystal size is one of the most important parameters of zeolite, which greatly affects its properties and performance. Here, the crystal size of Sn-Beta synthesized by hydrothermal route was tailored by adjusting the amount of crystal nuclei in the gel. Si-Beta that was treated with tetraethylammonium hydroxide (TEAOH) was used as the seed for synthesizing Sn-Beta. The seeds were studied by FT-IR, SEM, XRD and laser particle size analysis. It was found that the crystal size of the synthesized Sn-Beta depended on the concentration of TEAOH. Sn-Beta with minimum crystal size (about 500 nm) can be obtained using 0.5 mol L –1 TEAOH. Additionally, the crystal size distribution of Sn-Beta synthesized by the supernatant as seed was narrower than that synthesized by the solid residue as seed. The catalytic performance of Sn-Beta was tested in the conversion of ethyl levulinate to γ-valerolactone by Meerwein-Ponndorf-Verley reduction. Sn-Beta with small crystal size showed higher catalytic activity.