Preparation method of multi-component nano catalyst

Abstract

The invention relates to a preparation method of a novel high efficiency supported multi-component nano catalyst, which comprises the following steps: 1)using polyol and PVP as a reducing agent and a stabilizing agent, controlling the reduction temperature at 100-200 DEG C for 2-6 times, and acquiring highly dispersed copper platinum shell-case nanoparticles under inert atmosphere; 2)separating a nano compound, and dipping to a corresponded carrier; 3)under liquid phase condition, wherein the hydrogen is 0.5-5bar and pH value is 2-6, performing in-situ deposition of nano ferrite island on the surface of the platinum case, and forming the nano ferrite island catalysis material with stable structure corresponded to the nano copper platinum-core shell structure. The method has the advantages of extensive applicability, easy control, good process repeatability, and safe and reliable operation. The synthesized nanoparticles have the characteristics of uniform size, high dispersion and low cost, and can be widely used in CO selective oxidation, low temperature water gas transformation and electrochemical reactions.

Description

Technical field [0001] The invention relates to the preparation of a novel low-platinum high-efficiency load-type multi-component nano-catalyst, which realizes the high-efficiency utilization of precious metals and reduces the amount of precious metal catalysts. Background technique [0002] Supported precious metal catalysts show excellent catalytic performance in some important chemical processes and are widely used in many industrial processes, such as Pd / C catalysts in PTA hydrogenation, Pt / C catalysts in fuel cells, and automobile exhaust purification Pt-based multi-metal catalysts, etc. Due to the limited reserves of precious metals, the high price, and the inevitable loss of catalysts during the reaction, the replacement of precious metals in these important industrial catalysis processes has become a major subject of heterogeneous catalysis research. This is also of great significance to the development of basic catalysis theory and the practice of catalysis. After year...

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Problems solved by technology

For example, Dhavale et al. used ascorbic acid (AA) as a reducing agent to sequentially synthesize copper-platinum core-shell structure (CuPt / C) catalysts (Chem. Commun., 2011, 47, 3951 3953); It is difficult to ensure that the nano-copper particles are not oxidized by water after being reduced. In addition, the thickness of the Pt shell in the copper-platinum core-shell catalyst prepared by this method is still relatively large, and it is difficult to achieve a substantial reduction in the amount of Pt.

Zhou et al. used the sequential deposition method to prepare copper-platinum core-shell catalysts, that is, using ethylene glycol as a reducing agent and polyvinylpyrrolidone (PVP) as a protective agent to synthesize nano-Cu cores, and then sequentially deposited Pt to form CuPt nano-core-shell catalysts. (Angew.Chem.Int.Ed.2005,44,4539-4543), due to the lack of proper control in the sequential deposition of Pt, the thickness of the synthesized Pt shell is also large

Nilekar et al. used ethylene glycol as a reducing agent and polyvinylpyrrolidone (PVP) as a protective agent to synthesize nano Ru, Rh, Ir, Pd and Au cores, and then sequentially deposited 1-2 monoatomic layers of Pt shells to form RuPt, RhPt, IrPt , PdPt and AuPt nano-core-shell catalysts (J.Am.Chem.Soc., 2010, 132, 74187428); although the catalyst exhibits good catalytic activity in the selective oxidation of CO under hydrogen-rich conditions, the core of the catalyst Precious metals are still used, and catalyst costs are still high

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