Synthesis and characterization of mesoporous molecular sieve nanoparticles

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 center dot 9H(2)O), 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 m(2)/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.