Developing efficient seawater-electrolysis system for mass production of hydrogen is highly desirable due to the abundance of seawater.However,continuous electrolysis with seawater feeding boosts the concentration of ...Developing efficient seawater-electrolysis system for mass production of hydrogen is highly desirable due to the abundance of seawater.However,continuous electrolysis with seawater feeding boosts the concentration of sodium chloride in the electrolyzer,leading to severe electrode corrosion and chlorine evolution.Herein,the common-ion effect was utilized into the electrolyzer to depress the solubility of NaCl.Specifically,utilization of 6M NaOH halved the solubility of NaCl in the electrolyte,affording efficient,durable,and sustained seawater electrolysis in NaCl-saturated electrolytes with triple production of H_(2),O_(2),and crystalline NaCl.Ternary NiCoFe phosphide was employed as a bifunctional anode and cathode in simulative and Ca/Mg-free seawater-electrolysis systems,which could stably work under 500 mA/cm^(2) for over 100 h.We attribute the high stability to the increased Na^(+)concentration,which reduces the concentration of dissolved Cl-in the electrolyte according to the common-ion effect,resulting in crystallization of NaCl,eliminated anode corrosion,and chlorine oxidation during continuous supplementation of Ca/Mg-free seawater to the electrolysis system.展开更多
基金We acknowledge helpful discussion with Prof.Hongjie Dai.This work was supported by the National Natural Science Foundation of China(NSFC)the National Key Research and Development Project(Nos.2018YFB1502401 and 2018YFA0702002)+4 种基金the Royal Society and the Newton Fund through the Newton Advanced Fellowship award(NAF\R1\191294)the Program for Changjiang Scholars and Innovation Research Team in the University(No.IRT1205)the China Postdoctoral Science Foundation(No.BX20200336)the Fundamental Research Funds for the Central Universitiesthe long-term subsidy mechanism from the Ministry of Finance and the Ministry of Education of PRC.
文摘Developing efficient seawater-electrolysis system for mass production of hydrogen is highly desirable due to the abundance of seawater.However,continuous electrolysis with seawater feeding boosts the concentration of sodium chloride in the electrolyzer,leading to severe electrode corrosion and chlorine evolution.Herein,the common-ion effect was utilized into the electrolyzer to depress the solubility of NaCl.Specifically,utilization of 6M NaOH halved the solubility of NaCl in the electrolyte,affording efficient,durable,and sustained seawater electrolysis in NaCl-saturated electrolytes with triple production of H_(2),O_(2),and crystalline NaCl.Ternary NiCoFe phosphide was employed as a bifunctional anode and cathode in simulative and Ca/Mg-free seawater-electrolysis systems,which could stably work under 500 mA/cm^(2) for over 100 h.We attribute the high stability to the increased Na^(+)concentration,which reduces the concentration of dissolved Cl-in the electrolyte according to the common-ion effect,resulting in crystallization of NaCl,eliminated anode corrosion,and chlorine oxidation during continuous supplementation of Ca/Mg-free seawater to the electrolysis system.
