Banca de DEFESA: TAMILLE ALVES SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : TAMILLE ALVES SOUZA
DATE: 04/03/2024
TIME: 14:00
LOCAL: Sala de Seminários do Instituto de Química - UFBA
TITLE:

Fe, Cu and Alumina Catalysts for occurrence of reverse shift (RWGS) and activation of Carbon Dioxide

 

KEY WORDS:

CO2; CO; Fe; Cu; Ce; Al; reverse water gas shift; hydrogenation; DRIFTS in situ; methanol; CAMERE.

PAGES: 202
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SUMMARY:

Carbon dioxide(CO2) emission for atmosphere in the last years became a largest numbers, and consequently, has been causing severe climate change and ocean acidification. Therefore, the objective of this work was the preparation and evaluation of the catalyst Fe, Cu, Ce and Al base for reverse water gas shift reaction (RWGS), with the aim of CO2 activation to CO. The carbon monoxide (CO) is more reactive than CO2, so the CO production can be used as an intermediate step to facilitate a CO2 conversion in others products of industrial interest, as methanol, dimethyl ether (DME) from syn gas. First of all, the catalyst had been prepared for two methods (coprecipitation about the support and impregnation), in diferentes compositions off Copper in supported in Al2O3 or CeO2-Al2O3, in sequence, they were characterized ((FRX, TG/DTA, DRX, FTIR, MEV, TPR e Análise textural (BET e BJH)), tested in RWGS reaction, also a mechanism study was carried out with drifts in situ and a CAMERE simplificated study. The catalysts were active, selective and stable in the RWGS reaction, with CO2 conversions of up to 65%, CO selectivity of up to 100% and CO yield of approximately 60%, over reactions lasting 8 and 16 hours. The increase of quantity of copper in the catalysts favored the increase in CO selectivity. The incorporation of ceria in the catalysts did not result in a significant increase in activity, but contributed to the stability of the magnetite phase and less coke formation. Differences between catalyst preparation methods favored the formation of catalysts with different properties, however, they did not significantly influence the activity of the catalysts. So, the two preparation methods used in this work were efficient and are alternatives for the preparation of active catalysts in the RWGS reaction. From the in situ drifts tests of the RWGS reaction, it is concluded that the mechanism via format intermediates is the priority route in all catalysts studied, and that incorporation of CeO2 into catalysts interferes with the types of intermediate species that are formed in the reaction, in addition to became the RWGS reaction more selective. It was confirmed that iron oxide is the main active site for the RWGS reaction, however, the formation of CH4(g) only occurs in these sites, therefore, the insertion of Cu in the composition of the catalysts is essential to ensure selectivity from the catalyst to CO. Through the study of CO hydrogenation by in situ drifts, it was concluded that the catalysts studied in this work have the potential to produce methanol, olefins or ether. The CAMERE system doubled the methanol yield compared to direct CO2 hydrogenation. This approach shows that the RWGS reaction before the methanol synthesis is a promising route for increasing methanol yield, even at atmospheric pressure.

COMMITTEE MEMBERS:
Interno - 2356272 - ARTUR JOSE SANTOS MASCARENHAS
Externa ao Programa - 1965372 - FERNANDA TEIXEIRA CRUZ - nullPresidente - 282610 - HELOYSA MARTINS CARVALHO ANDRADE
Interno - 2362069 - RAILDO ALVES FIUZA JUNIOR
Externo à Instituição - RENAN TAVARES FIGUEIREDO - UNIT
Externa à Instituição - TEREZA SIMONNE MASCARENHAS SANTOS - UEFS
Interna - 1861434 - VALERIA CRISTINA FERNANDES