The invention relates to a three-way
NOx, CO and HC removing catalyst used in a
marine engine, and a preparation method thereof. The catalyst takes
cerium-
tin-
tungsten composite oxide as an
active component, takes one or more oxides of
cobalt, ferrum,
nickel,
copper,
lanthanum,
molybdenum,
manganese,
zirconium, silver and
yttrium as a
promoter, and takes AlSiTi
composite oxide as a carrier. A saturated
active component solution, a saturated
cobalt promoter ionic solution, strong acid
alumina gel,
diaspore, clayey,
titanium dioxide and an organic forming agent are stirred uniformly, mixed, aged and extruded for formation, and the integral type catalyst is obtained through
drying and
roasting. According to the invention, the catalyst has high
NOx removing efficiency, the active temperature window is wide, and the CO and HC removing efficiency is high in a low-temperature collaborated catalyzing manner. According to the catalyst, as the components of the catalyst are nontoxic and environmental-friendly, the catalyst has the advantages that the
mechanical strength is high, the vibration resistance as well as the
heat resistance is excellent, the preparation technology is simple, and the cost is low. The three-way
NOx, CO and HC removing catalyst is applicable to treatment of NOx, CO and HC in
tail gas of a marine
diesel engine, and is also applicable to treatment to
tail gas of other moving sources diesel engines such as automobiles.