Prepration Of Transition Metals Doped With Cuo-bi₂o₃ Catalysts And Study On Its Catalytic Synthesis Of 2-butyne-1,4-diol

2-Butyne-1,4-diol(BYD)contains both carbon-carbon triple bond and hydroxyl groups,which can participate in many chemical reactions,such as addition and dehydration condensation,and it's an important intermediate of organic chemical industry.BYD can be formed by formaldehyde and acetylene under the action of copper-bismuth catalyst.This method is called Reppe reaction,which is the only way to synthesize BYD in industry.Supported CuO-Bi2O3 catalysts have received extensive attention in this field due to their good catalytic activity and stability.However,the previous studies mainly focused on the selection of catalyst supports and the comparison of catalyst preparation methods.A large number of studies have shown that doping appropriate amount of transition metals can not only promote the good interaction between the active copper species and the support,but also improve the redox ability of the catalyst.However,there are few studies on doping and modification of copper-bismuth catalysts.In this paper,we use low temperature N2 adsorption-desorption,XRD,H2-TPR,XPS,TG-DSC and catalytic activity test techniques to study detailly the effect of different transition metals(Cr?Mn?Fe?Co or Ni),Mn loading,calcination temperature and the addition of CTAB on the structural property,redox ability,dispersion of copper species and catalytic activity of BYD synthesis under the action of CuO-Bi2O3 catalyst.Finally,the effect of technological conditions on the yield of BYD was investigated.Draw the following conclusions:1.The order of activity of CuO-Bi2O3 catalysts doped with different transition metals for the synthesis of BYD is CB-Mn>CB-Ni>CB-Fe?CB>CB-Co>CB-Cr.2.The doping of Mn can enhance the dispersion of copper,and the Mn of the low chemical valence in the course of the reaction has promoted the formation of Cu+.In addition,the presence of Mn or Ni inhibit acetylene polymerization on the catalyst surface.The doping of Fe has no obvious effect on the structure properties and redox ability of the catalyst.The doping of Co has intensified the aggregation of CuO,which is not conducive to the catalyst reduction process.The doping of Cr weaken the interaction between CuO and support.This leads to a serious loss of copper and a large amount of polyacetylene formed on the catalyst surface.3.When the doping amount of Mn is 3 mmol,the CuO is dispersed well.When the calcination temperature is 500?,the interaction between CuO and the carrier is good,and the aggregation of CuO is not excessive.When the addition of CTAB is 0.5 mmol,the dispersion state of CuO is the best,and the pore size of the catalyst is larger,which is beneficial to the desorption of the BYD in time.4.The optimum reaction conditions for the synthesis of BYD from formaldehyde and acetylene are as follows:DMSO-H2O is used as solvent,and the amount of catalyst is 5 g,and the reaction temperature is 95?,and the initial concentration of formaldehyde aqueous solution is 23%,and the pH value of the reaction solution after catalyst's reduction is 7.Under these conditions,the yield of BYD is the highest,which is 59.88%.