大电流密度下铬电极析氢行为  

Hydrogen Evolution on the Surface of a Chromium Electrode at High Current Density

作　　者：张晓顺[1] 姜效军[1] 

机构地区：[1]鞍山钢铁学院应用化学系,辽宁鞍山114002

出　　处：《过程工程学报》2002年第3期214-218,共5页The Chinese Journal of Process Engineering

摘　　要：在电解金属铬使用的7.5~20 A/dm2的大阴极电流密度下,测定了温度30~55oC及pH为2.1~2.5条件下的硫酸铵体系中铬电极表面析氢极化曲线,探讨了大电流密度下铬电极析氢的电化学过程. 结果表明,同一电流密度下,温度升高或pH值降低,析氢电位的绝对值变小. 电解铬时十六烷基三甲基溴化铵的加入使析氢极化曲线向负方向移动,可用作阻氢剂. 加入20 mg/L的十六烷基三甲基溴化铵,电流效率提高了8.1(. 由pH=2.1时的极化曲线得到不同温度及电流密度下铬电极表面一系列析氢过电位值. pH=2.1时的极化曲线的塔菲尔直线均通过lgi为1.72、过电位为1.35 V的公共点.At the high current density of 7.5~20 A/dm2 for chromium electrowinning, the polarization curves of hydrogen evolution on a chromium electrode at the conditions of 30~55oC and pH=2.1~2.5 were obtained to explore the electrochemical process of hydrogen evolution at high current density. It was found that the potential of hydrogen evolution decreases with the increase of temperature and decrease of pH. The polarization curves are shifted toward more negative when adding (CH3)3NC16H33Br (CTMAB) in the sulfate solution. It is shown that the CTMAB can suppress hydrogen evolution moderately. When electrowinning chromium in the solution with 20 mg/L CTMAB, the current efficiency is increased by 8.1%. A series of data of over-potential on the chromium electrode at different temperatures with pH=2.1 was obtained. All the Tafle plots at different temperatures pass through a common point with the coordinate lgi equal to 1.72 and over-potential to 1.35 V.

关 键 词：铬电极 电流密度 析氢 电化学 阴氢剂 

分 类 号：TF791[冶金工程—钢铁冶金]