Precious metal/carbon nanosheet composite material and preparation method thereof

Abstract

The invention discloses a noble metal / carbon nanosheet composite material and a preparation method thereof.The preparation method comprises the steps that noble metal salt, polyvinylpyrrolidone and urea are evenly mixed according to a certain proportion, heated and polymerized at the temperature of 160-240 DEG C till a solid state is completely formed and cooled to the room temperature, a precursor is obtained, and then the obtained precursor is subjected to heat preservation at the temperature of 160-240 DEG C to obtain the noble metal / carbon nanosheet composite material. And heating to 800-1000 DEG C under programmed temperature control and non-oxidizing gas protection for pyrolysis, and naturally cooling to room temperature to obtain the noble metal / carbon nanosheet composite material, the metal content can reach 40wt%, and the noble metal salt comprises platinum salt, palladium salt, rhodium salt, ruthenium salt and iridium salt. The technical problems that precious metal raw materials are not completely converted and precious metal is prone to falling off in the precious metal catalyst preparation process are solved, meanwhile, a double-element or multi-element precious metal composite material can be prepared, and the product does not need acid pickling, is environmentally friendly, is simple in preparation process and is beneficial to industrial large-scale production.

Description

technical field [0001] The invention relates to the technical field of catalyst preparation, in particular to a precious metal / carbon nanosheet composite material and a preparation method thereof. Background technique [0002] Precious metal catalysts are widely used in pharmaceutical synthesis, chemical production, energy catalysis and other fields due to their excellent catalytic activity and catalytic selectivity. Due to the small reserves and high price of precious metals in the earth's crust, it is very important to improve the utilization rate of precious metals and develop high-activity and high-stability precious metal catalysts. [0003] In the prior art, the carbon-supported precious metal nanomaterials are prepared by the traditional impregnation method. The precious metal salt solution is fully mixed with the activated carbon base, dried, and subjected to high-temperature reduction to prepare the carbon-supported precious metal catalyst. In the noble metal catal...

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Problems solved by technology

The noble metal composite material obtained by this method has the advantages of small noble metal particle size and narrow particle size distribution, but the preparation cost of metal organic framework compound is relatively high. In order to obtain noble metal nanoparticles, toxic reducing agents such as sodium borohydride or hydrazine hydrate are used. Insufficient reduction, resulting in waste of precious metal raw materials

Patent CN109569686A grows noble metal nanoparticles on the primary amine-modified activated carbon carrier by ultraviolet light reduction method. This invention uses halo to avoid the use of reducing agents such as sodium borohydride, which is environmentally friendly, but the photoreduction method has insufficient reduction of precious metal salt raw materials. The problem of low raw material utilization

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