Pd Monolayer on the 3D-Hollow-Porous Au Microsphere as an Advanced Electrocatalyst for the Ethanol Oxidation Reaction
De Ping Chen, Lei Yuan, Meng Jue Li, Wen Jing Han, Xu Dong Liu, Xi Chuan Liu, Chao Yang Wang
Abstract
Pd is a highly active non-Pt anode in direct ethanol fuel cells, and its morphology and structural composition heavily influence its electrocatalytic efficiency. In this study, three-dimensional (3D)-hollow Au microspheres (HNPs-Au) as a support for the Pd monolayer (HNPs-Au@Pd) were synthesized using a simple template method and galvanic replacement reaction. The experimental results and theoretical calculations show that the presence of HNPs-Au enhances the catalytic activity of ethanol oxidation in alkaline media, improving the electroactivity of metallic Pd. Benefiting from the 3D-hollow-porous structure and the significant synergistic impact between Au and Pd (balancing the adsorption energy of the intermediate and reactant molecules), HNPs-Au@Pd achieves a 10.8-fold mass activity and a 3.3-fold enhancement of the specific activity for the ethanol oxidation reaction when compared to commercial Pd/C. The present work not only enriches the preparation strategy of porous metal materials but also opens up a sector for the construction of anodic electrocatalysts with a wide range of applications.