Synthesis and characterization of mesoporous molecular sieve nanoparticles

Abstract

Mesoporous molecular sieve was prepared hydrothermally by a two-step method with materials of cetyltrimethyl ammonium bromide (CTAB), as a template, and sodium metaaluminate (NaAlO2) and sodium silicate (Na2SiO3·9H2O), as aluminum and silicon sources, respectively. The mesoporous molecular sieves are well ordered and have high thermal and hydrothermal stabilities. The as-prepared samples were characterized by powder X-ray diffraction (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), thermogravimetry-differential scanning calorimetry (TG/DSC), Fourier transform infrared spectroscopy (FT-IR) and nitrogen adsorption experiments. Particle size distribution was in the 30–50 nm range, BET surface area was more than 800 m2/g, thermal stability was higher than 1023 K, the mesoporous structure was not entirely damaged at a calcination temperature of 1123 K and there was no clear change in ordering degree, pore size, and surface area of the mesoporous molecular sieve after hydrothermal treatment at 373 K for 10 days. The activity and selectivity of benzene hydrogenation to cyclohexane by mesoporous molecular sieve-supported Pt was up to 100%. The catalytic activity didn’t decline in a reaction period of 30 h.