Abstracts Book - IMRC 2018

• SF3-P036
EVALUATION OF THE CATALYTIC ACTIVITY OF PT/CO-MN MIXED
OXIDES FOR TOLUENE OXIDATION VIA NAP-XPS UNDER IN
OPERANDO CONDITIONS
Luis Carlos Ojeda Perez 1 , Carlos Ostos 1 , Adriana Echavarria 1
1 Universidad de Antioquía, Grupo Catalizadores y Adsorbentes, Instituto de Química,
Colombia.
Volatile organic compounds (VOCs) are one of the main pollutants since they
produce photochemical compounds that deteriorate air quality and human
health. These VOCs come mainly from industrial processes and mobile sources.
To transform these substances into products with lower environmental impact,
several techniques have been developed, among which catalytic oxidation is
highlighted. For this purpose, noble metals and metal oxides supported in
catalytic devices have been used in recent years. Taking advantage of the
properties of both type of metals has led to design of catalysts in which the
synergy of hybrid multimetal systems is strengthened, given the coexistence of
noble metals decorating a mixture of metal oxides. For this study, we evaluated
the catalytic oxidation of toluene over Pt/Co-Mn mixed oxides synthesized by
auto-combustion, impregnated with cerium (3% wt.). An autocombustion
methodology was used to synthesize Co and Mn mixed oxides.
Nitrates of cobalt and manganese were used as source of non-noble metals and
oxidizers (O) and glycine was used as fuel (F) to drive the reaction. Molar ratios
of F/O used was 0.56 corresponding to stoichiometric conditions. The mixed
oxides with different Co/Mn molar ratios (0.5 – 1.0 – 2.0) were obtained through
the addition of the nitrates to the glycine, maintaining constant stirring. The
resulting solution was slowly evaporated until a gel was obtained. The gel was
then heated at 150°C for promoting the ignition process. Once the ignition
reaction was reached the powder produced was calcined at 500°C for 4 h to get
the corresponding oxide. The cerium impregnation was carried out by Charge-
Enhanced Dry Impregnation (CEDI) method. Finally, Pt/CoOx-MnOx-CeOx
system was obtained via Gas-bubble-assisted PVA protected route.
Microstructural, physicochemical and surface characteristics of the synthesized
materials were determinedrespect to their phase composition and mean
crystallite size (XRD technique), reducibility (H 2 -TPR), desorption characteristics
(O 2 -TPD), surface area (BET method) and the material morphology by scanning
electron microscopy (SEM). The catalytic oxidation mechanistic of 400 ppm of
toluene diluted in argon gas was studied via near ambient pressure X-ray