Preparation And Application Of Cu-Sn Bimetallic Nanomaterial Catalyst

As a new type of nanomaterials,most bimetallic nanocatalysts have many advantages such as high catalytic activity,high selectivity,high stability and low cost.These catalytic properties are determined by factors such as its structure,composition,morphology,particle size and morphology.By properly controlling the above factors,the bimetallic nanocatalyst can exhibit excellent activity.These influencing factors can usually be achieved by controlling the thermodynamic parameters?temperature,reduction potential.?and kinetic parameters?reactant concentration,diffusion amount,solubility,reaction rate?in the synthesis process.Bimetallic catalysts have attracted more and more attention in the fields of synthesis,catalysis,surface chemistry and structure.The bimetallic nanocatalyst reported in this work can adjust its catalytic performance by controlling its structure and external morphology.Metals,such as Cu and Sn are often used in heterogeneous catalytic reactions.Cu²⁺has strong activity in the oxidation of alcohols to aldehydes and ketones to esters.Sn is a good Lewis acid.Lewis acid plays a selective role in functional groups during organic and biochemical conversion.At the same time,Sn²⁺can enhance the positive charge of ketone carbonyl carbon to achieve the purpose of activating carbonyl carbon.In this paper,Cu-Sn bimetallic nanocatalysts were prepared by co-precipitation method.Their characteristics were tested and the catalysts were applied to the B-V oxidation rearrangement of cyclohexanone and the apparent activation energy of the kinetics was analyzed.The results show that the catalyst reduces the apparent activation energy of the cyclohexanone B-V reaction and accelerates the reaction rate.And the Cu-Sn bimetallic catalyst exhibits good catalytic activity in the conversion of cyclohexanone to cyclocaprolactone.The Cu-Sn molar ratio of 7:1 is the optimum ratio,the calcination temperature is 800°C?Cu-Sn-7:1-800-5?,the aldehyde to ketone ratio is 2.5:1,and 5 mL 1,,2-dichloroethane,The reaction temperature is 55°C,the reaction time is6 h,and the conversion and selectivity are both 99.9%.