Banca de DEFESA: MANUELA SILVA MARTINS DE OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MANUELA SILVA MARTINS DE OLIVEIRA
DATE: 16/09/2022
TIME: 14:30
LOCAL: Auditório do NUPPRAR
TITLE:

Hierarchically Structured Zeolites: A Study of Mesoporosity Insertion via Mechanochemistry.

KEY WORDS:

Zeolites, Hierarchies, Mechanochemistry, Milling.

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

Structurally, zeolites – when considered as aluminosilicates – basically consist of a three-dimensional network formed from silicon and aluminum tetrahedra that are interconnected by means of oxygen atoms. Due to their diverse properties and characteristics, it can be said that zeolites are the most used catalysts in the industry; however, the intrinsic microporosity of these materials has limited their application aimed at processing larger molecules. In this work, the influence of mechanochemical methods in obtaining zeolitic materials with hierarchical pore structure was studied, through the insertion of mesoporosity via dry grinding in a ball mill, seeking to obtain zeolites with greater accessibility of active sites. The zeolitic materials used in this process were Mordenite, Linde Type X and USY. In the application of the mechanochemical method, the variables rotation speed (200, 400 and 600 rpm) and rotation time (20, 40 and 60 min) were evaluated. For the mordenite zeolite, the acid materials previously submitted to a rotation speed of 200 rpm and a rotation time of 60 min showed more acceptable structural and textural maintenance compared to other milling studies. In addition, it kept the specific area practically unchanged and a considerable increase in the surface area and volume of mesopores. For Linde Type X zeolite, the low Si/Al ratio presented by the material ended up causing a structural collapse; which in turn made it difficult to apply this material. Finally, USY zeolite presented a profile similar to Mordenite zeolite materials, exhibiting less incisive structural changes at lower rotation speeds and times.

COMMITTEE MEMBERS:
Externo à Instituição - ADONAY RODRIGUES LOIOLA - UFC
Interno - 350509 - ANTONIO SOUZA DE ARAUJO
Externo à Instituição - EDUARDO RIGOTI - IFRN
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 2087667 - TIAGO PINHEIRO BRAGA