Resumo de eventos cient??ficos
Lanthanum doped ceria shaped nanostructures for oxidative coupling of methane
Registro en:
0000-0003-0708-2021
Autor
TRINDADE, FABIANE J.
DAMASCENO, SERGIO
OTUBO, LARISSA
SCHMAL, MARTIN
FLORIO, DANIEL Z. de
FONSECA, FABIO C.
FERLAUTO, ANDRE S.
BRAZIL MRS MEETING, 19th; INTERNATIONAL UNION OF MATERIALS RESEARCH SOCIETIES - INTERNATIONAL CONFERENCE ON ELECTRONIC MATERIALS
Resumen
The abundance of natural gas due to the advancements in exploration and extraction
technologies has increased the interest in the direct conversion of methane to C2 molecules
via oxidative coupling of methane (OCM) reactions [1]. The design of catalysts by tailoring
shape and oxygen vacancies has a significant impact on their performance [2]. Within this
context, in this work, the fine-tuning of structural defects of ceria rod-like and cube-like
shaped nanoparticles were performed via La3+ doping (LaxCe1-xO2-x/2) in molar ratios of
x=5-90 mol %. The morphology control was achieved by varying the hydrothermal synthesis
temperature from 110 ??C to 180 ??C. The characterization of LaxCe1-xO2-1/2 catalysts was
performed by SEM, HRTEM, XRD, and Raman spectroscopy. The catalytic performance of
the new nanomaterials for the OCM reaction was studied at 750 ??C with an in-line gas
chromatograph. In the LaxCe1-xO2-x/2 nanorods, the fluorite crystalline structure is essentially
maintained even for x = 0.6. The Raman spectra analysis indicates that the addition of La3+
leads and increases the formation of different amounts of extrinsic and intrinsic oxygen
vacancies. In addition, the catalytic tests for OCM reaction show that the LaxCe1-
xO2-1/2 (x=50%) nanorods catalyst have 25% of CH4 conversion and 48% of selectivity for
C2 products. The concentration of reactive oxygen species in the LaxCe1-xO2-1/2 (x=50%)
nanorods was crucial to improving the conversion rates and selectivity. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) FAPESP: 17/11937-4