降低电解水过程中传质过电压技术的研究进展

目前电解水技术中因反应过电压和传质过电压的存在使得电解效率较低，现有研究大多侧重开发活性更高的催化剂来降低反应过电压，提高电解效率。本文主要从气液流动和电解液内发生的传质的角度出发，对降低电解过程中传质过电压的技术进行综述：包括设置磁场，超声场，超重力场，并对其强化原理进行分析；另外，对通过优化电解过程操作条件来降低过电压的方法也进行了综述：包括改变电解槽操作温度、操作压力和供电方式。磁场变化可以加速离子迁移；超声场能有效降低电解液中弥散气泡的平均粒径和气泡脱离时间，加强传质；超重力会提供更强的传质驱动力，气泡也更易从电极表面脱离；温度升高可以加快反应速率，降低电能消耗，但需要提高压力来调节氢气在电解液中的溶解度，可能导致设备成本上升；脉冲电源供电比传统稳定的直流电源能耗更低。

ResearchProgressinTechnologytoReducetheTransferOvervoltageduringWaterElectrolysis

At present, due to the existence of reaction overvoltage and mass transfer overvoltage in water electrolysis technology, the electrolytic efficiency is low. Most researchers focus on the development of catalysts with higher activity to reduce the reaction overvoltage and improve the electrolytic efficiency. In this paper, we summarize the technology of reducing the mass transfer overvoltage in the electrolytic process from the point of view of gas-liquid flow and mass transfer that occurs in the electrolyte, including setting magnetic field, ultrasonic field and supergravity force field, and analyze their strengthening principle. In addition, the methods to reduce the mass transfer overvoltage by optimizing the operating conditions of the electrolytic process are also summarized, including changing the operating temperature, operating pressure and power supply mode of electrolytic cell. Magnetic field changes can accelerate the ion migration. The ultrasonic field can effectively reduce the average size and separation time of the dispersed bubbles in the electrolyte, and strengthen the mass transfer. The extra gravity provides a stronger force for mass transfer and makes it easier for bubbles to escape from the electrode surface.The increase of temperature can speed up the reaction rate and reduce the power consumption, but it needs to increase the operating pressure to adjust the saturation of electrolyte, which may lead to the increase of equipment cost. Pulse power supply has lower energy consumption than traditional stable DC power supply.