The synthesis of metal nanometer electrocatalysts with a two-dimensional (2D) structure or rich active sites has become a research hotspot in electrocatalysis. In this work, surfactant hexadecyltrimethylammonium bromide (CTAB) was used to assist the synthesis and assembly of Pd ultrathin nanosheet with the help of Mo(CO)6 in the start system. Pd nanochain composed of nanoparticles is obtained under the same condition, replacing CTAB with carrageenan only. Electrochemical measurements showed that the catalytic peak current density for the electrooxidation of ethanol can reach 2145 mA mg-1 for the Pd nanosheet assembly (NSA) and 1696 mA mg-1 for Pd nanochains. Pd nanosheet assembly also has a lower electron-transfer barrier, better catalytic stability, and antipoisoning performance than that of Pd nanochains. The mechanism of Pd nanosheets and nanochains catalysts the enhanced electrocatalytic activity toward ethanol oxidation has been discussed based on the experimental data.
Keywords: assembly; electrocatalysis; ethanol electrooxidation; nanosheet; palladium.