Nanostructured catalysts were successfully prepared by acidification of diatomites and the regeneration of used FCC
catalysts. The obtained samples were characterized by IR, XRD, SEM, EDX, MAS-NMR (27Al and 29Si), NH3-TPD and tested in catalytic pyrolysis of biomass (rice straw). The results showed that the similar bio-oil yield of 41,4% can be obtained by pyrolysis in presence of catalysts at 450°C as compared to that of the pyrolysis without catalyst at 550°C. The bio-oil yield reached a maximum of 42,55 % at the pyrolysis temperature of 500°C with catalytic content of 20%.
Moreover, by catalytic pyrolysis, bio-oil quality was better as reflected in higher ratio of H/C, lower ratio of O/C. This
clearly indicated high application potential of these new nanostructured catalysts in the production of bio-oil with low
SBA-15 nanostructured materials were synthesized via hydrothermal treatment and were functionalized with 3-
aminopropyltriethoxysilane (APTES). The obtained samples were characterized by different techniques such as XRD,
BET, TEM, IR and DTA. After functionalization, it showed that these nanostrucrured materials still maintained the
hexagonal pore structure of the parent SBA-15. The model enzyms chosen in this study were lipase and keratinase.
Lipase was a biocatalyst for hydrolyzation of long chain triglycerides or methyl esters of long chain alcohols and fatty
acids; keratinase is a proteolytic enzyme that catalyzes the cleavage of keratin. The functionalized SBA-15 materials
were used to immobilize lipase and keratinase, exhibiting higher activity than that of the unfunctionalized pure silica
SBA-15 ones. This might be due to the enhancing of surface hydrophobicity upon functionalization. The surface
functionalization of the nanostructured silicas with organic groups can favor the interaction between enzyme and the
supports and consequently increasing the operational stability of the immobilized enzymes. The loading of lipase on
functionalized SBA-15 materials was higher than that of keratinase. This might be rationalized by the difference in size
Hybrid nanoporous MCF, SBA-15 and MCM-41 materials were synthesized via hydrothermal treatment and
functionalized with 3-aminopropyltriethoxysilane (APTES) via post-synthesis grafting and sequently activated by
glutardialdehyde and then were used to immobilize D-amino acid oxidase (DAAO). The amino-functionalized materials
were characterized by various techniques: XRD, IR and N2 adsorption-desorption (BET). From characterization results, it
indicated that these materials still maintained their structure after functionalization. The data IR and TGA-DTA analysis
demonstrated the incorpotation of amine functional groups on the surface of APTES-functionalized samples. The DAAO
immobilized on functionalized materials exhibited higher catalytic activity and stability for conversion of cephalosporin
C (CPC) compare to those of non-functionalized one. Further more, the catalytic activity as well as stability of enzyme
decreased in order MCF > SBA-15 > MCM-41 with the decrease of their pore size.
SBA-15 and SBA-16 nanostucrured materials were synthesized via hydrothermal treatment and were functionalized with
3-aminopropyltriethoxysilane (APTES), and vinyltriethoxysilane (VTES). The obtained samples were characterized by
different techniques such as XRD, BET, IR and TEM. After functionalization, it showed that these nanostrucrured
materials were still maintained the hexagonal pore structure of the parent SBA-15 and cubic cage structure of the parent
SBA-16. The non-functionalized pure silica SBA-15 and SBA-16 as well as functionalized SBA-15 and SBA-16
materials were used to immobilize DAAO, which is industrially important enzyme for the production of glutaryl 7-amino
cephalosporanic acid (GL-7-ACA) from cephalosporin C (CPC). The obtained results revealed that functionalized SBA-
15 and SBA-16 materials exhibited higher enzymatic activity and stability than those of non-functionalized ones. This
might be due to the enhancing of surface hydrophobicity upon functionalization. The surface functionalization of the
nanostructured silicas with organic groups can enhance the interaction between enzyme and the supports and
consequently increasing the operational stability of the immobilized enzyme. The loading of enzyme on SBA-15
materials was higher than that on SBA-16 samples (both functionalized and non-functionalized types). This might be
explained by the difference in pore size and type (cylindrical for SBA-15 and bottle-neck for SBA-16) as well as
structure shape (hexagonal for SBA-15 and cubic cage for SBA-16) of both mesoporous materials. Additionally, nature
of functionalized groups significantly affected the enzymatic activity. Effects on surface binding force, nature of
functional groups, pore size of supports were investigated and discussed.
Rice straw, a waste agro-byproduct, which is abundant lignocellulose products from rice production, is a renewable
energy sources in Vietnam. Bio-oil from rice straw is produced by thermal and catalytic pyrolysis using a fixed-bed
reactor with heating rate 15oC/min, nitrogen as sweeping gas with flow rate 120ml/min. Final temperature of the
pyrolysis reaction is a significantly influence on product yield. The gas yield increased and the solid yield decreased as
the pyrolysis temperature increasing from 400oC to 600oC. The bio-oil yield reached a maximum of 48.3 % at the
pyrolysis temperature of 550oC. Mesoporous Al-SBA-15 was used as acid catalyst in pyrolysis of rice straw. The
obtained results showed that, in the presence of catalyst, yield of gas products increased, whereas liquid yield decreased
and solid product remained the same as compared to the non-catalytic experiments. The effect of nanostructured
catalysts on the product yields and distribution was investigated.
Fe containing SBA-15 mesoporous material was successfully prepared by direct synthesis and post-synthesis (atomic
implantation) methods. The obtained Fe-SBA-15 samples were characterized by different techniques such as XRD, BET,
TEM and UV-Vis. It showed that for both methods, Fe containing SBA-15 samples have highly ordered hexagonal
nano-structure with large pore size. It revealed the existence of both Fe species: Fe-tetrahedral coordinated and Fe-highly
dispersed species. However, higher portion of Fe-highly dispersed species in the samples prepared post-synthesis
(atomic implantation) was found. The Fe-SBA-15 catalysts were tested in catalytic oxidation of phenol and red phenol.
The results indicated that both Fe-incorporated and Fe-highly dispersed species were active sites. However, the latter
exhibited higher activity compared to the former ones.
Titanium-containing SBA-15 mesoporous materials with Si/Ti molar ratios of 25, 50 and 100 (Ti-SBA-15) were
successfully prepared by direct synthesized method using P123 as surfactant. The samples were characterized by XRD,
BET, TEM and UV-Vis. It revealed at low Ti-loading (Si/Ti of 50-100), titanium was completely incorporated into
SBA-15 framework, whereas at high Ti-loading (Si/Ti of 25) titanium was partially incorporated into SBA-15
framework, one part of Ti existed as extra-framework Ti (anatase phase). For comparison, Ti impregnated on Si-SBA-15
(Ti/SBA-15) was also prepared by postsynthesis method. In (*)this case, titanium was well dispersed onto the surface of
SBA-15. The catalytic activities of Ti-SBA-15 with different Ti-content and Ti/SBA-15 samples were tested in the
photocatalytic oxidation of red-phenol and in the photocatalytic reduction of Cr(VI) to Cr(III). The catalytic results
showed that both the Ti-SBA-15 and Ti/SBA-15 solids are also the good catalysts for total photooxidation of red phenol.
Especially, the tetrahedral coordinated titanium can oxidize red phenol much deeper than well dispersed titanium
particles does. For photocatalytic reduction, the activities mainly depend on the number of Ti, not the state of Ti.
Fe-SBA-15 was successfully synthesized by hydrothermal treatment in one step . Different techniques such as XRD, BET, HRTEM, UV-vis have been used to characterize the Fe-SBA-15 samples. Obtained results have shown that the obtained Fe-SBA-15 samples have highly ordered hexagonal mesostructure with large pore size of about 64Å. Most Fe species in the Fe-SBA-15 were tetrahedrally coordinated. The sample exhibited high stability by calcination at high temperature to remove the template. The Fe-SBA-15 catalysts were tested in catalytic oxidation of phenol and photocatalytic oxidation of chlorophenol. The results indicated that Fe-SBA-15 exhibited the high catalytic activity in these reactions.