电解煤浆制氢阳极的制备及电催化活性研究

Preparation of the Catalytic Electrodes and Study on Their Catalytic Activity for Electro-oxidation of Coal Slurry

将钛片进行预处理,用处理后的钛片作为电极基体,然后用循环伏安法在钛基体上沉积制备了Pt/Ti,Pt-Ru/Ti,Pt-Ir/Ti,Pt-Ru-Ir/Ti催化电极,通过扫描电镜(SEM)、X射线衍射(XRD)、电子能谱(EDS)以及等离子发射光谱(ICP)等方法对所制备电极进行了表征,包括电极表面形貌、组分的沉积状态、催化层成分组成以及电极寿命等;在煤浆电解过程中,采用两电极体系,对所制备电极的电催化活性进行了测试.结果表明:所制备的电极催化活性都高于同面积的铂片电极,含有Ru,Ir的二元催化电极的活性好于镀铂催化电极.在一定范围内,随着Ru元素比例增大,电极活性增强,而Ir元素含量过大,电极活性反而稍微降低,所以Pt-Ir(1∶0.5)/Ti,Pt-Ru(1∶5)/Ti两电极的催化活性相对较好.本文所制备的三元催化电极的催化活性低于二元催化电极.Pt-Ru/Ti电极催化活性最好,相同条件下具有最大的电解电流,H2的电解效率可达95%以上.

Ti based metal or composite catalytic electrodes were prepared by depositing Pt-M catalysts on pure Ti substrate in cyclic voltammetry and were characterized by SEM, XRD, EDS and ICP. The electro-catalytic activity of the electrodes prepared for the electro-oxidation of coal slurry was measured in a two electrode system. Results showed that the electro-catalytic activity of the electrodes was far better than that of the pure Pt electrode. The Ir or Ru addition to Pt/Ti can improve the catalytic activity. With the proportion of Ru increasing to a certain extent, the electro-catalytic activity became better. However, the Ir was otherwise. So the Pt-Ir（1 ： 0.5）/Ti and Pt-Ru（1 ： 5）/Ti electrodes had the best catalytic activity. The electro-catalytic activity of the ternary electrodes prepared above was not as good as that of the binary electrodes. The Pt-Ru/Ti electrode had the best electro-catalytic activity and its electrolysis efficiency of hydrogen was up to 95%.