Hierarchically 3D Porous Ag Nanostructures Derived from Silver Benzenethiolate Nanoboxes: Enabling CO2 Reduction with a Near-Unity Selectivity and Mass-Specific Current Density over 500 A/g
Hierarchically 3D Porous Ag Nanostructures Derived from Silver Benzenethiolate Nanoboxes: Enabling CO2 Reduction with a Near-Unity Selectivity and Mass-Specific Current Density over 500 A/g
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DOI：
10.1021/acs.nanolett.0c00518
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发表时间：
2020-04-08
期刊：
影响因子：
10.8
通讯作者：
Sun, Yugang
中科院分区：
文献类型：
--
作者：
Abeyweera, Sasitha C.;Yu, Jie;Sun, Yugang
通过电化学还原苯硫酚银纳米盒，制备了具有多级孔结构的银纳米结构。多孔银纳米结构对CO2的电化学还原具有上级催化性能。在高阴极电位下，将CO2还原为CO的法拉第效率可以接近100%，这得益于Ag表面上的再吸附的苯硫酚根离子，其可以抑制析氢反应（HER）。密度泛函理论计算表明，巯基苯修饰的Ag表面上的H键是抑制HER.CO2还原的质量比活性可以超过500 A/g，这是因为多尺度的多孔性最大化了活性物质向Ag表面的扩散和远离Ag表面的扩散.所合成的银纳米结构的独特的多尺度孔隙率和表面改性使它们成为一类有前途的催化剂，用于在质子电解质中电化学还原CO2以实现最大的活性和选择性。
Silver nanostructures with hierarchical porosities of multiple length scales have been synthesized through electrochemical reduction of silver benzenethiolate nanoboxes. The porous Ag nanostructures exhibit superior catalytic performance toward electrochemical reduction of CO2. The Faradaic efficiency of reducing CO2 to CO can be close to 100% at high cathodic potentials, benefiting from the readsorbed benzenethiolate ions on the Ag surface that can suppress the hydrogen evolution reaction (HER). Density functional theory calculations using the SCAN functional reveal that the disfavored H binding on the benzenethiolate-modified Ag surface is responsible for inhibiting the HER. The mass-specific activity of CO2 reduction can be over 500 A/g because the multiple-scale porosities maximize the diffusion of reactive species to and away from the Ag surface. The unique multiscale porosities and surface modification of the as-synthesized Ag nanostructures make them a class of promising catalysts for electrochemical reduction of CO2 in protic electrolytes to achieve maximum activity and selectivity.