石油焦基炭材料及其作为电解Bunsen反应产物阳极的应用

Carbon Materials Based on Sulfur-containing Petroleum Coke and Their Application as Anode Materials for Bunsen Reaction Products

选用4种不同硫含量的石油焦为原料,经过KOH活化制备氮、硫双掺杂炭材料,对其微观形貌、石墨化程度、孔径结构和表面元素状态等进行了表征分析;制得的石油焦基炭材料用于HI(1 mol/L)+H_(2)SO_(4)(0.5 mol/L)(Bunsen反应产物)溶液电解阳极,通过循环伏安、线性扫描和交流阻抗等电化学测试,考查了其电催化I^(-)氧化生成I^(-)/I^(-)的电化学性能。探讨氮、硫原子掺杂和孔结构对I;氧化的作用,得出N提供主要活性位,吡啶氮可作为最佳电催化活性中心,较高的杂原子含量有助于提高材料的电化学性能。较多的介孔有助于半径较大的I_(3)^(-)从电极到溶液的溶解和扩散,降低阻抗增加电化学活性。优选出最佳性能的材料为原料硫含量4.6%(质量分数)的石油焦制备的炭材料。

Four kinds of petroleum coke with different sulfur content were used as raw materials to prepare sulfur and nitrogen co-doped carbon materials by potassium hydroxide activation. The microstructure, graphitization degree, pore size structure, and surface element state of the prepared materials were characterized and analyzed. Four carbon-based materials prepared by petroleum cokes with different sulfur content were applied as HI(1 mol/L) +H_(2)SO_(4)(0.5 mol/L) solution electrolytic anode materials. The electrochemical properties of their electrocatalytic I^(-)oxidation to I_(2)^(-)/I_(3)^(-)were investigated. The electrochemical properties of the materials, such as cyclic voltammetry, linear scanning, and AC impedance, were studied. Combined with the characterization results, the effect of nitrogen and sulfur doping on catalytic oxiding of I^(-)was discussed. It was concluded that pyridine nitrogen could be used as the catalytic active center. Meanwhile, S in graphitic plane network structure could induce polarization of adjacent C and N atoms, and a new electrocatalytically active center is formed. More mesoporous pores contribute to the dissolution and diffusion of I_(3)^(-)ions from electrode surface into solution. The carbon material prepared with sulfur content of 4.6% has the highest pyridine-N content, and the larger average pore size is conducive to the diffusion of I;ions, so the corresponding electrochemical activity is optimum.