Banca de QUALIFICAÇÃO: RAFAEL CHAVES LIMA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAFAEL CHAVES LIMA
DATE: 27/06/2022
TIME: 14:00
LOCAL: videoconferência
TITLE:

Layered solids structural modifications to obtain catalysts.

KEY WORDS:

layered solids, synthesis, structural modification, catalysis.

PAGES: 150
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

The layered solids Magadiite, Na-RUB-18, and potassium hexaniobate were hydrothermally synthesized and modified by many methodologies aiming isomorphous substitution and pillaring processes in order to generate potential catalysts. The materials were characterized by different techniques, namely, XRD, elemental analysis by ICP-OES and CHN, FTIR, NIR, DRUV-Vis, Raman spectroscopies, Solid-state MAS  29Si and 27Al NMR, N2 and CO2 physisorption, and FEG-SEM and TEM microscopies. Isomorphous substitutions with Al, Ti and Nb were carried out in the magadiite leading to various coordination sites. Also, some these procedures led to MOR and GIS topologies zeolite crystallization. For pillaring processes, the lamellar solids were previously swollen and verified that each one interacts differently with the intercalant agent. Magadiite was pillaring with pure silica and Al, Ti, and Nb mixed pillars, which present tetra-, penta-, and hexacoordination sites. It was found that to the processes involved metals the methods that promote a better homogenization and delayed the hydrolysis reactions tend to give more tetracoordinated Al and Ti sites, and pentacoordinated Nb sites. Na-RUB-18 was pillared with pure silica pillars and his textural properties were slightly different to the magadiite. Potassium hexaniobate was successfully submitted to silica pillaring giving a new porous double layered pillared material.

BANKING MEMBERS:
Interno - 1086214 - ANDERSON DOS REIS ALBUQUERQUE
Externo à Instituição - CHRISTIAN WITTEE LOPES - UFRGS
Externa à Instituição - HELOISE DE OLIVEIRA PASTORE - UNICAMP
Externa ao Programa - ***.566.270-** - LINDIANE BIESEKI - UFRN
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER