%0 Journal Article
%T On Effective Locations of Catalytic Active Sites in Phase Boundary Catalyst
%A Hadi Nur
%A Nur Hidayah Mohd Ran
%A Nursyafreena Attan
%A Shigeru Ikeda
%J ITB Journal of Science
%D 2012
%I 
%X Zeolite loaded with alkylsilane-covered titanium oxide was found to be more effective than nonporous silica counterpart as ¡°phase-boundary catalyst (PBC)¡± to promote the epoxidation of alkenes with aqueous hydrogen peroxide. It was demonstrated that the phase-boundary catalyst system required neither stirring to make an emulsion nor addition of a cosolvent to make a homogeneous solution to drive the reaction. However, some basic facts about them remain unclear, such as the question as to where an effective location of the active sites of PBC: is it the external surface of the catalysts or in their pore? In order to elucidate this problem, TS-1, HZSM-5 and zeolite loaded with alkylsilane¨Ccovered sulfonic acid in which the location of the active sites mainly inside the pore system are chosen as model catalysts. Catalytic activity of TS-1 and HZSM-5 catalysts were examined after modification with n-octadecyltrichlorosilane (ODS). Their activities are compared with zeolite loaded with alkylsilane-covered titanium oxide particles, in which the active sites are on their external surface in reactions of 1-octene with aqueous H2O2 and cyclohexene with water as model reactions. It was suggested that the location of the active sites on the external surface plays an important role in ¡±phase-boundary catalysis¡± phenomenon.
%K location of catalytic active sites
%K phase-boundary catalysis
%U http://journal.itb.ac.id/download.php?file=A12126.pdf&id=1239&up=3