摘要
To acquire the synergy effects between Sn and Cu for the jointly high Faradaic efficiency and current density,we develop a novel strategy to design the Sn-Cu alloy catalyst via a decorated co-electrodeposition method for CO2 electroreduction to formate.The Sn-Cu alloy shows high formate Faradaic efficiency of 82.3%±2.1% and total C1 products Faradaic efficiency of 90.0%±2.7% at^-1.14 V vs.reversible hydrogen electrode(RHE).The current density and mass activity of formate reach as high as(79.0±0.4)mA cm^-2 and(1490.6±7.5)m A mg^-1 at^-1.14 V vs.RHE.Theoretical calculations suggest that Sn-Cu alloy can obtain high Faradaic efficiency for CO2 electroreduction by suppressing the competitive hydrogen evolution reaction and that the formate formation follows the path of CO2→HCOO*→HCOOH.The stepped(211)surface of Sn-Cu alloy is beneficial towards selective formate production.
CO2电化学还原反应(CO2RR)为可再生能源储存及CO2转化提供了有效途径.目前,CO2转化为C1化学品(如甲酸和CO等)被认为是CO2RR最可行的途径之一.甲酸具有高的氢含量及易于存储和运输等特点,通常被用作燃料电池的液体燃料.目前,Sn、Cu、In、Bi等金属作为CO2RR制备甲酸的催化剂被广泛报道,但是这些催化剂的选择性和质量活性即使在高的过电位下仍然不佳.因此,将Sn或Cu与其他元素合金化是提高CO2RR质量活性的有效方法,通过调整合金表面电子结构来调节反应中间体的结合能,可以达到提高CO2RR性能的目的.本文利用修饰的电化学共沉积法一步制备了Sn-Cu合金催化剂,并提高其CO2RR质量活性.在^-1.14V(vs.RHE)电位下,Sn-Cu合金的甲酸法拉第效率为82.3%±2.1%,甲酸产物的质量活性达到(1490.6±7.5)mA mg^-1,且具有良好的稳定性.理论计算表明,Sn-Cu合金通过抑制竞争性的析氢反应来获得高的甲酸法拉第效率.甲酸生成路径为CO2→HCOO*→HCOOH,Sn-Cu合金的(211)台阶表面有利于选择性地生成甲酸.
作者
Ke Ye
Ang Cao
Jiaqi Shao
Gang Wang
Rui Si
Na Ta
Jianping Xiao
Guoxiong Wang
叶克;曹昂;邵加奇;王刚;司锐;塔娜;肖建平;汪国雄(State Key Laboratory of Catalysis,Dalian National Laboratory for Clean Energy,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education,College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin 150001,China;Shanghai Synchrotron Radiation Facility,Zhangjiang Laboratory,Shanghai 201204,China)
基金
supported by the National Key R&D Program of China(2017YFA0700102)
the National Natural Science Foundation of China(21573222,91545202,21802124,91945302 and 91845103)
Dalian National Laboratory for Clean Energy(DNL180404)
Dalian Institute of Chemical Physics(DICP DMTO201702)
Dalian Outstanding Young Scientist Foundation(2017RJ03)
Liaoning Revitalization Talents Program(XLYC1907099)
the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020200)
the financial support from CAS Youth Innovation Promotion(2015145)
the financial support from the China Postdoctoral Science Foundation(2018M630307 and 2019T120220)。
