Wicks Joshua, Jue Melinda L, Beck Victor A, Oakdale James S, Dudukovic Nikola A, Clemens Auston L, Liang Siwei, Ellis Megan E, Lee Geonhui, Baker Sarah E, Duoss Eric B, Sargent Edward H
Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada.
Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550, USA.
Adv Mater. 2021 Feb;33(7):e2003855. doi: 10.1002/adma.202003855. Epub 2021 Jan 14.
The electrosynthesis of value-added multicarbon products from CO is a promising strategy to shift chemical production away from fossil fuels. Particularly important is the rational design of gas diffusion electrode (GDE) assemblies to react selectively, at scale, and at high rates. However, the understanding of the gas diffusion layer (GDL) in these assemblies is limited for the CO reduction reaction (CO RR): particularly important, but incompletely understood, is how the GDL modulates product distributions of catalysts operating in high current density regimes > 300 mA cm . Here, 3D-printable fluoropolymer GDLs with tunable microporosity and structure are reported and probe the effects of permeance, microstructural porosity, macrostructure, and surface morphology. Under a given choice of applied electrochemical potential and electrolyte, a 100× increase in the C H :CO ratio due to GDL surface morphology design over a homogeneously porous equivalent and a 1.8× increase in the C H partial current density due to a pyramidal macrostructure are observed. These findings offer routes to improve CO RR GDEs as a platform for 3D catalyst design.
通过电合成从一氧化碳制备增值多碳产物是使化学生产摆脱化石燃料的一种有前景的策略。特别重要的是合理设计气体扩散电极（GDE）组件，以便在大规模和高速率下进行选择性反应。然而，对于这些组件中气体扩散层（GDL）在一氧化碳还原反应（CO RR）方面的理解有限：特别重要但尚未完全理解的是，GDL如何调节在大于300 mA cm的高电流密度条件下运行的催化剂的产物分布。在此，报道了具有可调微孔率和结构的可3D打印含氟聚合物GDL，并探究了渗透率、微观结构孔隙率、宏观结构和表面形态的影响。在给定的外加电化学电势和电解质选择下，观察到由于GDL表面形态设计，与均匀多孔等效物相比，C₂H₄:CO比率提高了100倍，并且由于金字塔形宏观结构，C₂H₄分电流密度提高了1.8倍。这些发现为改进作为3D催化剂设计平台的CO RR GDE提供了途径。
