Abstracts Book - IMRC 2018

• SF3-P004
CORRELATION OF RH PARTICLE SIZE WITH CO CHEMISORPTION:
EFFECT ON CATALYTIC OXIDATION OF MTBE
Adrián Cervantes Uribe 1 , Gloria Alicia del Angel Montes 2 , Gilberto Torres Torres 1 , Armando
Vázquez Zavala 3 , Federico González 4 , Adrián Cordero García 1 , Reyna Ojeda López 5
1 Universidad Juárez Autónoma de Tabasco, Catalisis, Mexico. 2 Universidad Autónoma
Metropolitana, Catalisis, Mexico. 3 Universidad Autónoma Metropolitana, Física, Mexico.
4 Universidad Autónoma Metropolitana, Ingeniera e Hidráulica, Mexico. 5 Universidad Autónoma
Metropolitana, Superficies, Mexico.
This study, was conducted to relate the chemisorption of CO (linear interaction
and gem dicarbonyl) with specific size of rhodium particle and the influence of
these on the catalytic oxidation reaction of Methyl tert-butyl ether (MTBE). For
the above, TiO 2 was synthesized by sol-gel method under acidic conditions. The
TiO 2 support obtained was used to deposit Rh (1 wt%) by incipient wetness
impregnation method. To control particle size, the Rh/TiO 2 materials were
crystallized for 3h using different reduction conditions during heat treatment.
Analysis by X-ray diffraction (XRD), transmission electron microscopy (TEM),
Fourier-transform infrared spectroscopy (FTIR) and inductively coupled plasma
optical emission spectrometry (ICP-OES) were conducted to characterize the
synthesized materials. The results obtained the TEM micrographs indicated that
the average particle size was 1, 1.3 and 4.2 nm for RhTi1, RhTi2 and RhTi3,
respectively. From the histogram analysis of each micrographs, we found that
the gem-dicarbonyl interaction was typical of Rh particles ≤ 1.5 nm and the linear
interaction, bridged interaction and dentate interaction was observed in
particles ≥ 1.6 nm. We conclude that the CO chemisorption observed by FTIR-
CO, relates not only to the distribution of Rh particles on the TiO 2 surface but
also to the particle size. Therefore, the RhT1 catalyst, in which only was
observed: interaction gem-dicarbonil, smaller particle size (≤ 1.5 nm) and greater
metallic dispersion; was the most active in the oxidation reaction of MTBE. This
research confirms that the chemisorption of CO is related to the metallic
dispersion and particle size, but also contributes with the range of Rh particle
size in which each type of CO chemisorption is carried out.
Acknowledgment:
This work is financially supported by the Faculty of Chemical Sciences of the
Universidad Autónoma Metropolitana (UAM) and CONACYT (Project SEP-
CONACYT CB-2013-01-220191). Special gratitude to the A. Vázquez, and the F.