Rational design of PdBi nanochains with grain boundaries for enhanced ethanol oxidation reaction

Over the years, direct ethanol fuel cells have aroused wide concern in sustainable development. At the same time, researchers are committed to developing low-cost and high-efficiency fuel cells, especially catalysts as the core component. In this work, PdBi nanochains (NCs) were synthesized by a brief one-step method and applied as catalysts. Among these PdBi NCs catalysts, the Pd 79 Bi 21  NCs displayed the topmost mass activity of 1.74 A mg Pd −1 for ethanol oxidation reaction, which was three times that of commercial Pd/C. In addition, it performed well in terms of temporal stability. According to a series of characterization results, its excellent performance was attributed to several merits: (i) the electronic structure of Pd was modified after doping Bi, which could weaken the interaction between Pd and CO or other intermediates; (ii) defects (the grain boundaries, for instance) would provide abundant active sites in the catalytic reactions ; (iii) the nanochain-based structure was conducive to the complete exposure of active reaction sites and the improvement of stability.