Banca de DEFESA: FERNANDO ERICK SANTOS DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : FERNANDO ERICK SANTOS DA SILVA
DATE: 07/08/2023
TIME: 08:30
LOCAL: meet.google.com/joh-izsp-hvf
TITLE:

Synthesis and characterization of WC and Ni nanocatalysts supported on Al2O3 and MCM-41 for dry reforming of methane.

KEY WORDS:

nanocatalyst; tungsten carbide; surface area; methane reforming

PAGES: 88
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

The search for new sources of renewable energy is a global concern for increasingly sustainable development. Among renewable energy sources, hydrogen (H2) is seen as an alternative to the use of fossil fuels due to its minimal environmental impact. This study aimed to obtain nickel (Ni) and tungsten carbide (WC) catalysts supported on alumina (Al2O3) and MCM-41 for hydrogen production via methane dry reforming (CH4). Various transition metals such as Co, Pd, Pt, Ru, Rh, Ir, and Ni can be used in the reforming reaction. Tungsten carbide behaves similarly to Pt in several catalytic reactions, owing to the modification of tungsten's electronic structure by the addition of carbon. In this context, we were able to synthesize catalysts of (Ni10%wt) and (WC10%wt) supported on Al2O3 via incipient wetness impregnation with distilled water, and catalysts of (Ni10%wt), (WC10%wt), (Ni2%wt-WC8%wt), (Ni5%wtWC5%wt), and (Ni8%wt-WC2%wt) supported on MCM-41 via incipient wetness impregnation with ethanol. The (WC) used in the study was produced by carbothermic reduction of ammonium paratungstate (APT). The obtained material was then characterized by X-ray diffraction (XRD), X-ray fluorescence, Raman spectroscopy, nitrogen adsorption and desorption using the BET method, and scanning electron microscopy (SEM). Based on the results, it was possible to conclude that the WC synthesis process was efficient, producing nanometric carbides (15.5 nm) with irregular particle shapes and sizes. Incipient wetness impregnation proved to be an effective method for all obtained catalysts, with the nickel phase showing better dispersion on the alumina and MCM-41 supports than the WC phase. However, when both active phases (WC-Ni) are present, the dispersion on the supports significantly improves for the WC active phase. The (Ni10%wt/Al2O3) catalyst presented a specific surface area of 3.60 m²/g, while the (WC10%wt/Al2O3) catalyst had a specific surface area of 2.2 m²/g. The Ni10%wt/MCM-41 catalyst had a specific surface area of 588.56 m²/g, whereas the WC10%wt/MCM-41 catalyst showed a surface area of 870.63 m²/g, significantly increasing compared to the nickel active phase (Ni10%wt/MCM-41).

COMMITTEE MEMBERS:
Presidente - 2266607 - FABIO JOSE PINHEIRO SOUSA
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externo ao Programa - 345842 - UILAME UMBELINO GOMES - UFRNExterna à Instituição - MARIA JOSE SANTOS LIMA
Externo à Instituição - RAFAEL ALEXANDRE RAIMUNDO