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.
Novel nano TS-1, Ti-MCM-41 and Ti-SBA-15 analogues were successfully synthesized by hydrothermal treatment
using TS-1 nano-seeds as precursors. The samples were characterized by IR, XRD, FESEM, TEM and BET. The
characterization results revealed that the synthesized TS-1 had microstructure with crystal size of 50 - 60 nm, Ti-MCM-
41 and Ti-SBA-15 analogues had mesostructure with high ordering. The samples were tested in photocatalytic oxidation
of Red Phenol and in photocatalytic reduction of Cr(VI) to Cr(III). The samples exhibited high activities in both
reactions. Photocatalytic performances of all samples were compared and discussed.
Nano-sized TiO2 samples were successfully synthesized by both methods: sol-gel and hydrothermal treatment. The
samples were characterized by XRD and FESEM, TEM. The XRD results revealed TiO2 samples consisted of pure
anatase phase and/or mixture of anatase-rutile phases depending on the synthesis condition. By SEM-TEM, the particle
size of all TiO2 samples was ca. 20-50nm. Nanosized TiO2 samples were tested in the photocatalytic oxidation of redphenol
and in the photocatalytic reduction of Cr(VI) to Cr(III). All samples were active in both reactions, however, a
difference in photocatalytic activities between samples was observed. For comparison, P25 Degussa was also
investigated. Photocatalytic performances of the samples were discussed.
A novel mesoporous material Ti-MSU has successfully synthesized by hydrothermal treatment using nanoseed-TS-1 as precursors. The sample was characterized by different techniques such as: IR, XRD, BET, UV-Vis. The obtained results revealed that the product was highly ordered mesostructure with pore size of 24 Ao and the wall of crystalline nature. Ti-MSU was tested in the photocatalytic oxidation of chlorophenol. Ti-MSU sample showed much higher activity compared to that of TS-1 and P25 in the photocatalytic oxidation of orthochlorophenol.