Different Interlayer Anions Controlled Zinc Cobalt\nLayered Double Hydroxide Nanosheets for Ethanol Electrocatalytic Oxidation

Abstract

Layered\ndouble hydroxides (LDHs) have been known as highly desired\nanode materials in the alkaline electrolyte. With regard to non-noble\nmetal electrocatalysts, the interlayer spacing of LDHs has important\ninfluences on the electrocatalytic activity toward ethanol oxidation.\nHerein, ZnCo-LDHs with different interlayer spacing controlled by\ndifferent interlayer anions (NO₃^–, Cl^–, and CH₃COO^–) are used\nas effective non-noble metal electrocatalysts for the ethanol oxidation\nreaction (EOR). The interlayer spacing of three non-noble metal electrocatalysts\nfollows the order: ZnCo-LDH-CH₃COO^– (0.763\nnm) > ZnCo-LDH-Cl^– (0.733 nm) > ZnCo-LDH-NO₃^– (0.719 nm). ZnCo-LDH-CH₃COO^– exhibits the highest mass activity (345.4 mA mg^–1) for the EOR, which is 1.22 and 1.37 times higher\nthan that of ZnCo-LDH-Cl^– (283.8 mA mg^–1) and ZnCo-LDH-NO₃^– (252.8 mA mg^–1), respectively, attributed to the enlarged interlayer\nspace. This work proposes a potential mechanism of the catalytic process\ntoward the EOR, which may provide a new idea to design non-noble metal\nelectrocatalysts with high catalytic activity in direct ethanol fuel\ncells (DEFCs).