Single-Site Cu-Doped PdSn Wavy Nanowires for Highly Active, Stable, and CO-Tolerant Ethanol Oxidation Electrocatalysis.

Developing a catalyst to break the tradeoff relationship between the catalytic activity and antipoisoning property toward the ethanol oxidation reaction (EOR) is of critical importance to the development of direct ethanol fuel cells (DEFCs), but remains challenging. Here, we developed a unique class of single-site Cu-doped PdSn wavy nanowires (denoted as SS Cu-PdSn WNWs) with promoted activity and durability toward alkaline EOR. Detailed characterizations reveal the atomic isolation of Cu species dispersed on the surface of the PdSn WNWs with distinct wavy structure and grain boundaries. The created SS Cu-PdSn WNWs exhibit an enhanced EOR performance in terms of mass activity, which is higher than those of PdSn WNWs, commercial Pd black, and commercial Pd/C, respectively. Moreover, the SS Cu-PdSn WNWs can also show improved stability as compared to other catalysts due to the improved antipoisoning property from the unique surface anchoring structure. Further investigations demonstrate that the doped SS Cu can strongly inhibit the adsorption of CO and promote the reaction process of EOR. DFT results reveal that the doped Cu shifts down the d-band center of PdSn, thereby modifying the adsorption of intermediates and reducing the reaction barrier of EOR. This work maps a pathway for optimally boosting EOR performance with surface engineering via atomic doping.