以Ce3+/Ce4+为媒质间接电合成1,4-萘醌

探讨了以Ce³⁺/Ce⁴⁺为媒质的1,4-萘醌间接电化学合成反应。考察了液相氧化、Ce³⁺电解氧化过程的影响因素,并进行了萘醌的间接电合成实验。结果发现,硫酸浓度、溶液温度对铈离子的氧化能力和电化学反应活性具有重要的影响;当温度为70℃、硫酸浓度为1.0 mol·L^-1时,液相氧化反应的收率最高(85.8%)。Ce³⁺电解氧化的最优条件为:电流密度50 mA·cm^-2、硫酸浓度1.0 mol·L^-1、温度为50℃,其电流效率可达90.6%;间接电合成实验过程中萘醌的平均收率达85.7%,Ce³⁺电解氧化的平均电流效率达87.8%,并且电解过程具有良好的稳定性,表明该技术具有良好的产业化应用前景。

Indirect electrochemical synthesis of 1,4-naphthoquinone mediated by Ce3+/Ce4+

Indirect electrochemical synthesis of 1,4-naphthoquinone was studied by using Ce³⁺/Ce⁴⁺ as mediator.The influence factors related to the processes of liquid phase oxidation of naphthalene and electrochemical oxidation of Ce³⁺ were investigated, and indirect electrochemical synthesis of 1,4-naphthoquinone was also conducted.The experimental results showed that concentrations of H₂SO₄ and solution temperature had significant influence on oxidative ability and electrochemical reactivity of cerium ions.The highest yield of 1,4-naphthoquinone (85.8%) could be obtained during liquid phase oxidation in 1.0 mol·L^-1 H₂SO₄ at 70℃.The current efficiency of electrochemical oxidation of Ce³⁺ could reach up to 90.6% with current density of 50 mA·cm^-2 in 1.0 mol·L^-1 H₂SO₄ at 50℃.Excellent results were achieved during indirect electrochemical synthesis of 1,4-naphthoquinone.The tests were cycled for six times, and average yield of 1,4-naphthoquinone and current efficiency of electrochemical oxidation of Ce³⁺ were 85.7% and 87.8% respectively.These indicated that this technology could have a good prospect of commercialization.