Mesoporous carbon obtained from rice husk for hydrogen adsorption.

JULIANA M. JUÁREZ; JHOAN F. TÉLLEZ; E. LAURA MOYANO; MARCOS B. GÓMEZ COSTA

Bangkok

Congreso; 12th International Conference on Advanced Materials and Engineering Materials (ICAMEM2023); 2023

Rice Husk contains a high silica content (~93% by weight), which implies considerable potential for its use in the manufacture of high value-added products, such as mesoporous molecular sieves (MCM and SBA series), biocomposites, zeolites (ZSM-5), concrete-based materials, carbon dioxide adsorbents and photocatalysts. Carbon mesostructured from Korea (CMK) is a family of Ordered Mesoporous Carbon (OMC). These materials are of great interest due to their high surface area, thermal stability, chemical inertness, and biocompatibility. They are normally obtained by the so-called replication synthesis (or nanocasting), which is a reverse duplicate preparation method of siliceous nanostructures. In this work, it is proposed to develop a silicon mesoporous material MCM-41 from rice husk, and its carbon counterpart to be used in hydrogen adsorption.To obtain the precursor SiO2, the rice husk was washed several times with distilled water to remove adhering dirt and impurities, then it was dried at 100 ºC and a treatment with 3M HCl was carried out to remove metallic impurities. After washing and drying, the shell obtained was calcined at 700 ºC for 6 hours. The synthesis of the mesoporous siliceous material MCM-41 was carried out by hydrothermal synthesis using cetyltrimethylammonium bromide (CTAB) as surfactant. The replica of the MCM-41 mesoporous material was obtained using the nanocasting technique, with sucrose as carbon source and MCM-41 as template (R-MCM-41).The materials successfully synthesized were characterized by X-ray diffraction, SEM, textural properties, and transmission electron microscopy analyses. The siliceous material MCM-41 has a BET surface of 710 m2/g and an average (BJH) pore diameter of 3 nm. Regarding the carbon replica of said MCM-41 material, the BET area is 860 m2/g and presents an average (BJH) pore diameter of 3.5 nm.The obtained replica of MCM-41 significantly improved H2 storage behavior compared to CMK-3 type nanostructured carbon (2.4% by weight at -196,15 oC and 10 bar). The synthesized material shows promise in absorbing hydrogen by weak binding forces (physisorption). In this work, it was possible to successfully synthesize the MCM-41 nanomaterial from rice husk residues, its carbonaceous replica was obtained using the nanocasting technique. This carbon nanostructured material exhibits This carbon nanostructured material exhibits high hydrogen adsorption at 10 bar and -196,15 oC, which makes it a promising material for this application.