摘要:
A catalyst support for purification of exhaust gas includes a porous composite metal oxide, the porous composite metal oxide containing alumina, ceria, and zirconia and having an alumina content ratio of from 5 to 80% by mass, wherein after calcination in the air at 1100° C. for 5 hours, the porous composite metal oxide satisfies a condition such that standard deviations of content ratios (as at % unit) of aluminum, cerium and zirconium elements are each 19 or less with respect to 100 minute areas (with one minute area being 300 nm in length×330 nm in width) of the porous composite metal oxide, the standard deviation being determined by energy dispersive X-ray spectroscopy using a scanning transmission electron microscope equipped with a spherical aberration corrector.
摘要:
A catalyst support for purification of exhaust gas includes a porous composite metal oxide, the porous composite metal oxide containing alumina, ceria, and zirconia and having an alumina content ratio of from 5 to 80% by mass, wherein after calcination in the air at 1100° C. for 5 hours, the porous composite metal oxide satisfies a condition such that standard deviations of content ratios (as at % unit) of aluminum, cerium and zirconium elements are each 19 or less with respect to 100 minute areas (with one minute area being 300 nm in length×330 nm in width) of the porous composite metal oxide, the standard deviation being determined by energy dispersive X-ray spectroscopy using a scanning transmission electron microscope equipped with a spherical aberration corrector.
摘要:
A catalyst for purification of exhaust gas in which Pd-based nanoparticles and ceria nanoparticles are supported on a composite metal oxide support containing alumina, ceria, and zirconia, wherein a molar ratio (Ce/Pd) of Ce and Pd supported on the support is 1 to 8, a proximity α between Pd and Ce is 0.15 to 0.50, wherein the proximity α is determined, based on Pd and Ce distribution maps in an element mapping image of energy dispersive X-ray analysis, by the following formula (1):
α =
∑
j = 0
N - 1
∑
i = 0
M - 1
(
(
I (
i , j
)
-
I ave
)
(
T (
i , j
)
-
T ave
)
)
∑
j = 0
N - 1
∑
i = 0
M - 1
(
I (
i , j
)
-
I ave
)
2
-
∑
j = 0
N - 1
∑
i = 0
M - 1
(
T (
i , j
)
-
T ave
)
2
,
( 1 )
a Pd dispersity after a heat-resistance test at 1050° C. for 25 hours is 0.8% or more.
摘要:
A core-shell oxide material comprises: a core which comprises a ceria-zirconia based solid solution powder having at least one ordered phase of a pyrochlore phase and a κ phase; and a shell which comprises an alumina based oxide disposed on at least a portion of a surface of the core.