Department of Chemistry, Faculty of Science, Sri Chandrasekharendra Saraswathi Viswa Mahavidyalaya (SCSVMV University), Enathur, Kanchipuram 631 561, India.
J Colloid Interface Sci. 2012 Dec 1;387(1):213-20. doi: 10.1016/j.jcis.2012.08.002. Epub 2012 Aug 15.
This work demonstrates the use of amino functionalized Mg-phyllosilicate clay/Nafion nanocomposite film embedded with Pt nanoparticles (Pt/AC/N) for catalyzing oxygen reduction reaction (ORR) in sulphuric acid medium. Pt/AC/N nanocomposite films were surface characterized using transmission electron microscope. Cyclic and linear scan voltammetry studies were carried out under hydrodynamic conditions taking rotating-ring disc electrode (RRDE) as the working electrode. The effects of clay content, Pt mass loading, electrode rotation rate, and temperature on the ORR kinetics were studied. The Tafel slopes were found to vary between 118 and 126 mV dec(-1) indicating a good ORR kinetics. The exchange current density values calculated after mass transfer correction ranged from 5.8×10(-7) to 2.4×10(-6) A cm(-2). From the RRDE disc currents, Koutecky-Levich plots were constructed and the ORR mechanism was found to follow a four electron path with minimum H(2)O(2) formation of ∼1.6%. The effect of temperature on ORR kinetics was found at 25, 40, and 50°C. The energy of activation calculated to be 7.68 kJ mol(-1) and comparable to the standard Pt/C catalyzed ORR systems.
这项工作展示了在硫酸介质中使用氨基功能化的 Mg-层状硅酸盐粘土/ Nafion 纳米复合材料膜嵌入 Pt 纳米粒子（Pt/AC/N）来催化氧还原反应（ORR）。使用透射电子显微镜对 Pt/AC/N 纳米复合材料膜进行了表面特征分析。在水动力条件下进行了循环和线性扫描伏安法研究，以旋转环盘电极（RRDE）作为工作电极。研究了粘土含量、Pt 质量负载、电极旋转速度和温度对 ORR 动力学的影响。发现 Tafel 斜率在 118 至 126 mV dec(-1) 之间变化，表明具有良好的 ORR 动力学。经过质量传递校正后计算的交换电流密度值范围为 5.8×10(-7) 至 2.4×10(-6) A cm(-2)。从 RRDE 盘电流构建了 Koutecky-Levich 图，并且发现 ORR 机制遵循四电子路径，H(2)O(2)的最小形成率约为 1.6%。在 25、40 和 50°C 下研究了温度对 ORR 动力学的影响。计算出的活化能为 7.68 kJ mol(-1)，与标准 Pt/C 催化的 ORR 系统相当。
