Non-loading type nano-scale composite carbon-noble metal catalyst as well as preparation method and application thereof

Abstract

The invention discloses a non-loading type nano-scale composite carbon-noble metal catalyst as well as a preparation method and application thereof. The catalyst is granular and the particle size is not greater than 20nm; each particle is formed by compounding one noble metal particle and one carbon dot; the average size of the carbon dots is 1 to 10nm and the average size of the noble metal particles is 1 to 10nm; noble metal is one of platinum, palladium, iridium, ruthenium and rhodium; the mass ratio of the noble metal to carbon is (0.01 to 0.3) to (0.5 to 2.5). The non-loading type nano-scale composite carbon-noble metal catalyst provided by the invention is applied to reaction of synthesizing chloroaniline through photo-thermal catalysis and hydrogenation via chloronitrobenzene, and has the characteristics of high conversion rate, high catalytic activity, high reaction speed and high stability.

Description

(1) Technical field [0001] The invention relates to a non-loaded nano-sized composite carbon-noble metal catalyst and a preparation method thereof, as well as the application of the catalyst in the photothermal catalysis of selective hydrogenation reaction of chloronitrobenzene. (2) Technical background [0002] Chloroaniline is an important organic chemical raw material and intermediate widely used in fine chemical fields such as medicine, pesticides, dyes, etc. It occupies a very important position in the production of fine chemicals at home and abroad. For the production of chloroaniline , as a traditional industrial production method: reduction methods such as iron powder reduction method, alkali sulfide reduction method and electrochemical reduction method, due to the problems of large energy consumption and serious pollution, the traditional reduction method is gradually abandoned at home and abroad to prepare halogenated anilines. The hydrogenation reduction method ha...

AI Technical Summary

Problems solved by technology

However, during the catalytic hydrogenation reduction of chloronitrobenzene to chloroaniline, dechlorinated by-products will be generated, which will cause equipment damage and product quality decline. Therefore, the most efficient and stable catalyst for research is catalytic hydrogenation A key step in the reduction method

[0003] In the existing reports, researchers have used the following methods to construct new hydrogenation catalyst structures and active sites to achieve the purpose of inhibiting dechlorination: 1) Enhance the strong interaction between the metal and the support [ACS Catalysis, 2013, 3(6):1386-1396]; 2) Doping heteroelements on the surface of the carrier, such as nitrogen [New Carbon Materials, 2016, 31(3):287-292]; 3) Constructing dual / multi-component catalysts, Such as Pt / C(Fe)[J.Applied CatalysisA:General,2012,429:17-23], etc., this type of catalyst has the characteristics of high activity and strong practical production applicability, but its selectivity and stability need to be improved , and they all use the method of loading precious metals on the carrier, which often leads to uneven distribution of precious metals and incomplete exposure of active sites, resulting in low utilization of precious metals and unsatisfactory catalytic performance. Higher activity is still urgently needed in industrial applications. , selectivity and stability of industrial catalysts

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