| dc.creator | Alvarez, Juan | |
| dc.creator | Valderrama, Gustavo | |
| dc.creator | Pietri, Eglé | |
| dc.creator | Pérez Zurita, M. Josefina | |
| dc.creator | Urbina de Navarro, Caribay | |
| dc.creator | Sousa-Aguiar, Eduardo Falabella | |
| dc.creator | Goldwasser, Mireya | |
| dc.date | 2015-07-21T15:49:27Z | |
| dc.date | 2015-07-21T15:49:27Z | |
| dc.date | 2015-07-21 | |
| dc.date.accessioned | 2022-10-28T01:13:50Z | |
| dc.date.available | 2022-10-28T01:13:50Z | |
| dc.identifier | 022-5528 | |
| dc.identifier | http://hdl.handle.net/10872/11533 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/4945311 | |
| dc.description | Perovskite-related mixed-oxides based on La
Ni Nb and La Sr Ni Nb were synthesized by the auto
combustion method to use as precursors materials for the
catalytic reforming of methane at 700 8C, atmospheric
pressure, CH4:CO2 = 1:1. LaNiO3 and LaNbO4 were used
as reference. XRD analysis show that the synthesis method
produce a new series of precursor family formed by a
mixture of oxides where Ni crystallized as part of a
perovskite and Ruddlesden–Popper structure while Nb
formed lanthanum orthoniobate LaNbO4, a scheelite-type
structure alternating with oxide layers, with phase distribution
depending on niobium content. For Nb (x B 0.3) Ni
crystallizes as LaNiO3 perovskite-type oxide while for Nb
(x C 0.7) it forms mainly the orthoniobate phase LaNbO4 a
scheelite-type structure. At higher calcined temperatures
(*1100 C) La2Ni0.8Nb0.2O4 was formed with a Ruddlesden–
Popper structure consisting of three perovskite
type layers along the c-axis alternating with a layer of the
rock salt type phase. TEM analysis showed the presence of
cubic particles with sizes varying between 5 and 60 nm
depending on the extent of substitution of Ni by Nb.
Reduction of the perovskite-related precursor oxides produced
a series of Ni0/La2O3–NbOx oxides with high
metallic dispersion which favors the activity and stability
of the catalysts. Introduction of doping quantities of Sr into
LaNi0.8Nb0.2O3±k structure produced a mixture of oxides
with Sr dissolved in the lanthanum orthoniobate LaNbO4
scheelite-type structure due to the similarity of ionic radii
of La and Sr. Under the reaction conditions conversions
near the thermodynamic equilibrium were attained which
remains for long periods of time assessing the stability of
the synthesized catalysts. | |
| dc.language | en | |
| dc.subject | Ni–Nb-mixed oxides | |
| dc.subject | Dry methane reforming | |
| dc.subject | Perovskites-related structures | |
| dc.subject | Ruddlesden– Popper structure | |
| dc.subject | Scheelite structure | |
| dc.title | Ni–Nb-Based Mixed Oxides Precursors for the Dry Reforming of Methane | |
| dc.type | Article | |
