Aminolysis of styrene oxide catalyzed by microporous silica with longitudinal and spiral pore channels prepared from rice husk ash

• Published in: Materials today : proceedings 2018, Vol.5 (10), p.21584-21593
• Main Authors: Iqbal, Anwar, Hou, T.K., Shaari, U.S., Adam, Farook, Abu Bakar, N.H.H, Wilson, L.D., Jaafar, N.F., Hazwan Hussin, M., Afandi, M.A.
• Format: Article
• Language: English
• Subjects: Aminolysis; Rice husk ash; Silica; Supermicropore; Ultramicropore
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2018.07.007

An amorphous silica catalyst (MS-AI) with longitudinal and spiral pore channels was prepared from rice husk ash via sol-gel method. The BET surface area of MS-AI was 1016 m2g-1, while NLDFT results indicate that the pore size of MS-AI was variable: ultramicropore (6 Å) and supermicropore (11- 20 Å). The t-plot results indicate an estimated micropore surface area of 947 m2g-1 with a micropore volume of 0.41 cm3g-1. The presence of the Q2 signal along with the Q3 and Q4 signals indicate the condensation of silanol groups to siloxane groups within the framework of the catalyst is incomplete. The catalytic activity was tested for the aminolysis of styrene oxide with aniline. The reaction is proposed to take place via hydrogen bond interactions between the surface silanol bonds of the catalyst with styrene oxide. High levels of conversion of styrene oxide (92-95 %) occurred at 50 °C for 4 hours. The catalyst was selective towards ß-amino alcohol (96.8-98.5 %) where benzalaniline was the minor product obtained.