Universidad Nacional Autónoma de México - CNyN
Universidad Nacional Autónoma de México - CNyN
Universidad Nacional Autónoma de México - CNyN
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1st International Symposium on Nanoscience and Nanomaterials<br />
spectra show that the films are transparent at 70% in visible range. The room temperature photoluminescence<br />
(PL) measurements of ZnO-SiO 2 composite films show UV emission (3.16 eV) which is generate by<br />
annealing in oxygen atmosphere. The thickness of the films annealing was measured by ellipsometry, this<br />
value obtained was between 640 and 660 nm.<br />
P-022<br />
CATALYTIC OXIDATION PROCESSES OVER GOLD NANOPARTICLES SUPPORTED ON<br />
MESOPOROUS SILICA<br />
N. Bogdanchikova 1,a , A. Pestryakov 1,2 , I. Tuzovskaya 1 , T.A. Zepeda 1 , M.H. Farias 1 , O.Martynyuk 1 , 2<br />
1 Centro <strong>de</strong> Nanociencias y Nanotecnología, <strong>Universidad</strong> <strong>Nacional</strong> Autónoma <strong>de</strong> México, Apdo. Postal 14, C.<br />
P. 22800, Ensenada, México<br />
2 Tomsk Polytechnic University, Tomsk 634050, Russia<br />
a nina@cnyn.unam.mx<br />
Keywords: gold, nanoparticles, active sites, CO oxidation, alcohol oxidation.<br />
Supported gold nanoparticles are well-known as active catalysts for various important processes.<br />
Structural and electronic properties of gold nanoparticles supported on Ce, Ti and Fe-modified hexagonal<br />
mesoporous silica (HMS) were studied by XRD, TEM, FTIR, UV-vis. spectroscopy, XPS, N 2 adsorption and<br />
EDS techniques. These materials were used as heterogeneous catalysts for CO oxidation as well as liquidphase<br />
aerobic oxidation of alcohols to al<strong>de</strong>hy<strong>de</strong>s. A comparative analysis of spectroscopic and catalytic data<br />
allows suggesting that Au n δ+ clusters or/and Au + ions are responsible for the activity in the low-temperature<br />
region (< 200 o C); neutral Au n clusters are active in the range 200-400 o C; and gold nanoparticles may catalyze<br />
the high-temperature CO oxidation. The experiments also showed that nanosized gold supported on pure<br />
HMS and on HMS modified by Ce, Ti or Fe oxi<strong>de</strong>s is an effective catalyst for the oxidation of alcohols to<br />
al<strong>de</strong>hy<strong>de</strong>s and esters, for example, benzyl alcohol to benzal<strong>de</strong>hy<strong>de</strong> and methyl benzoate. The activation effect<br />
of modifiers seems to be associated with their influence on the electronic state of the supported gold.<br />
P-023<br />
COMPARISON OF (Ni OR Co)Mo/Al 2 O 3 CATALYSTS SYNTHESIZED BY MICROEMULSION<br />
José Luis Munguía Guillén 1,a , José António <strong>de</strong> los Reyes Heredia 1,b and Tomás Viveros García 1,c<br />
1 <strong>Universidad</strong> Autónoma Metropolitana – Iztapalapa. Av San Rafael Atlixco No.186 Col.Vicentina. C.P.09340<br />
Del. Iztapalapa DF México.<br />
a jlmgg@hotmail.com, b jarh@xanum.uam.mx, c tvig@xanum.uam.mx<br />
Keywords: Microemulsion, nanoparticles, catalysts, hydro<strong>de</strong>sulfurization.<br />
The preparation of catalysts by the microemulsion method has allowed the <strong>de</strong>velopment of supported<br />
active phases with interesting properties in their catalytic performance This method provi<strong>de</strong>s nanostructured<br />
supported metals with interesting applications as heterogeneous catalysts. The water/oil microemulsion uses<br />
surfactant molecules to stabilize the water/oil interface of nanosized water droplets, that are dispersed in an<br />
organic solvent. These water droplets consist in an aqueous solution of the metals precursors. In this work,<br />
NiMo and CoMo /Al 2 O 3 catalysts were prepared by this method and the influence of the metal content was<br />
evaluated in the HDS of dibenzothiophene. The synthesis procedure was studied in or<strong>de</strong>r to establish the set<br />
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