Method for preparing nanocrystal metal-doped catalyst

Abstract

The invention discloses a method for preparing a nanocrystal metal-doped catalyst. The method comprises the following steps: dissolving a compound of Ce and Zr to form a mixed metal saline solution; dissolving a compound of Ta and Nb to form a doping agent metal solution; dissolving urea in water to prepare a urea aqueous solution; heating the urea aqueous solution until the urea aqueous solution is boiled; slowly adding the doping agent metal solution into the mixed metal saline solution, then quickly adding the boiled urea aqueous solution, standing for 20-30 minutes, and performing crystallization and sedimentation; filtering and washing sediments; drying the sediments, and calcining under the temperature of 350-500 DEG C. The catalyst is of a framework structure with holes; the average crystallite size is smaller than 4 nm, and the average aperture is 3-6 nm; the surface area of the framework structure is larger than about 280m<2> / cm<3>. According to a water gas transformation reaction method, carbon-containing fuel is reacted with the catalyst for providing water gas transformation reaction according to claim 1; the water gas transformation reaction is carried out under the temperature of greater than 450 DEG C; a mixed metal oxide-loaded catalyst achieves an effect of promoting CO to be converted into CO2; the catalysis performance is high, and the conversion rate is high.

Description

technical field [0001] The invention relates to a method for preparing a nanocrystal metal-doped catalyst. Background technique [0002] A durability target or criterion for supported catalysts often used in the water gas shift reaction is their ability / inability to remain active for a period of at least 40,000 hours. Specifically, it is not unusual for a catalyst to exhibit a drop in activity during the first hours of operation, the most active sites on a heterogeneous catalyst are generally the least stable. The optimum time for determination of new or onset of useful activity using the benchmark procedure for reactor / catalyst design depends on the sum of the effects of the various deactivation mechanisms. The important mechanism in the absence of coking and site poisoning due to feed impurities is migration of the active metal phase and agglomeration of very small <0.5 nm metal clusters into >1 nm and often >2 nm crystallites. For noble metals in the absence of...

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Problems solved by technology

On the other hand, for a given catalyst final form, excess pore volume can be used to reduce the amount of effective surface area within a given reactor volume, thereby limiting the catalytic effect in a given reactor volume