This paper describes the investigations of the
catalytic activity in soot oxidation over well-defined iron
oxide based materials. The nanostructuration of iron oxide
by potassium into tunnelled (KFeO
2
) and layered
(K
2
Fe
22
O
34
) ferrites and the surface promotion with CeO
2
results in the marked increase in the catalytic activity
(decrease of the ignition temperature down to 210
°
C and
T
10 %
to 310
°
C). The measurements of the catalysts work
function showed that both nanostructuration and surface
promotion with ceria of the best KFeO
2
phase led to
increase of the electron availability (decrease of the work
function). Strong correlation of the catalytic activity in soot
combustion of the Ce–K–Fe–O systems with the work
function value was revealed for the first time in the model
studies, and can be used as a guideline for optimisation of
the real catalytic filters.
keywords in English:
iron oxide, diesel, potassium, oxidation, cerium oxide, promotion, soot, ferrite, work function