Synthesis and stability of CoMCM-41 mesoporous molecular sieve using cetyltrimethyl ammonium bromide as a template by two-step hydrothermal method

Abstract

CoMCM-41 mesoporous molecular sieves were synthesized by two-step hydrothermal method using sodium silicate and cobalt chloride as raw materials and cetyltrimethyl ammonium bromide as a template. The as synthesized samples were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), specific surface area analysis, Fourier transform-infrared spectroscopy (FT-IR) and N 2 physical adsorption. The experimental results show that the as synthesized CoMCM-41 mesoporous molecular sieve has a specific surface area over 700 m 2/g and an average pore size in a range of 3.4–4.5 nm. After the template was effectively removed by calcination at 550 °C, the pore structure was not damaged. On the other hand, specific surface area, pore size and pore volume of the as synthesized CoMCM-41 mesoporous molecular sieves were not markedly changed after hydrothermal treatment at 100 °C for 5 days or thermal treatment at 650 °C for 3 h. The synthesized CoMCM-41 mesoporous molecular sieve has good thermal and hydrothermal stability. The stability of the as synthesized CoMCM-41 mesoporous molecular sieve is related to the different sequence of adding raw material.