Medium-low temperature solid-solid reaction method for preparing nano grade cerium-zirconium composite oxide solid solution

Abstract

The present invention is medium and low temperature solid-solid reaction process for preparing nanometer level composite cerium-zirconium oxide solid solution. The composite cerium-zirconium oxide solid solution including cerium oxide and zirconium oxide is prepared with cerium carbonate and zirconium carbonate as material, and through adding oxalic acid in certain amount, mixing, ball milling and calcining. The composite cerium-zirconium oxide solid solution has high crystallization degree, crystal grain size of 20-70 nm, and specific surface area of 80-100 sq m / g. The preparation process has the advantages of no solvent used, no effluent, simple operation, low power consumption, environment friendship, etc.

Description

technical field [0001] The invention relates to a preparation method of a nano-scale cerium-zirconium composite oxide solid solution, which is mainly used as a catalyst additive for automobile exhaust purification, a fuel cell and a raw material for functional ceramics. The invention specifically relates to the preparation of nano-scale cerium by a medium-low temperature solid-solid reaction method Zirconium composite oxide solid solution method. Background technique [0002] With the development of the automobile industry, automobile exhaust has become the main cause of air pollution in today's cities. It seriously affects people's health and the growth of animals and plants. Therefore, it is very important to study catalysts and additives with excellent performance. Nano-scale cerium-zirconium oxide solid solution is a good catalyst additive for automobile exhaust purification. Due to its addition, it not only reduces the amount of precious metals used in the catalyst, but...

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Problems solved by technology

They have their own advantages and disadvantages: although the high-temperature solid-phase synthesis method is simple in process, the product has a large particle size and must be mechanically processed by airflow crushing to reach the nanometer level, and consumes energy; the cerium-zirconium composite oxide solid solution particles prepared by the hydrothermal method The crystal grains are fully developed, the crystal shape is good and the size is controllable, the particle purity is high, the dispersion is good, the particle size distribution is small, but the cost is relatively high; the co-precipitation method keeps the metal salt concentration at a low level, which is conducive to crystallization. The nucleation of the particles inhibits the growth of the particles. The components of the co-precipitation method are evenly distributed, and the addition of different stabilizers can diversify the crystal forms of the prepared particles; the products prepared by the sol-gel method have good uniformity and small grain radius. The surface area is large, and the disadvantage is that the organic solvent is toxic and high-temperature calcination is easy to cause agglomeration, and the process is long. All wet chemical preparation processes have a large amount of waste liquid, which does not meet the requirements of green chemistry.

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