Synthesis of hydrothermally stable MCM-41 by the seed crystallization and its application as a catalyst support for hydrodesulfurization

Abstract

MCM-41 is one of the weak hydrothermally stable members in M41s mesoporous silica family. Therefore, in the present work, an attention has been focused to improve its hydrothermal stability as well as to achieve more acidic sites on its surface structure, in order to make it a good candidate as a support for hydrodesulfurization (HDS) catalysts. Hydrothermally stable MCM-41 (MCM-41(HS)) has been successfully prepared by the seed crystallization method. The synthesized material was analyzed by the powder X-ray diffraction (XRD), nitrogen adsorption-desorption, ammonia-temperature programmed desorption (NH3-TPD), chemisorption of carbon monoxide (CO chemisorption), elemental analysis (EA) and solid NMR techniques. The characterization results showed that the hydrothermal stability of MCM-41(HS) was significantly improved due to presence of highly crosslinked framework walls, while the mesopore system remained highly ordered. The synthesized MCM-41(HS) has been initially used here as a support to prepare Mo/MCM-41(HS) catalyst for HDS application. The increased zeolitic phase in the wall of mesostructure is believed to increase the HDS activity of MCM-41(HS) supported Mo catalyst in contrast with conventional Al-MCM-41 supported Mo catalyst. (c) 2012 Elsevier Ltd. All rights reserved.