烟碱电化学合成烟酸的研究

Indirect Electrochemical Synthesis of Nicotinic Acid from Nicotine

提出了一种合成烟酸的新方法———间接电合成法。在分隔型电解槽中 ,用Pb PbO2 阳极将Cr3+ 氧化成Cr2 O72 - ,用Cr2 O72 - 为氧化剂对烟碱进行氧化可获得合格烟酸 ,产率在 80 %以上。还原所得Cr3+ 循环利用。优选条件为 :c(H2 SO4 ) =3.0～ 4.0mol·L- 1,电流密度 60 0A m2 ,c(Cr3+ ) =0 .2 5～ 0 .45mol·L- 1。此时 ,Cr3+ 的转化率为 70 %左右 ,电流效率可达 80 %。

Electro oxidation of Cr\-2(SO\-4)\-3 on Pb/PbO\-2 anode in H\-2SO\-4 solution was carried out in a divided cell separated by an anion exchange membrane.The influences of various factors such as concentration,current density,temperature,etc,were investigated.Under typical conditions appreciated,the average anodic current efficiency could reach 80%.Oxidation of nicotine with Cr\-2O\-7\+\{2-\} was also studied.Results showed that the process employed gave higher yield,better product quality and less pollution.