Ni-doped ultra-small size PdSn hexagonal nanoplates for catalyzing formic acid oxidation

Designing and synthesizing low-cost, high-performance electrocatalysts remains an important challenge for the commercialization of liquid fuel cells. Herein, a novel PdSnNi hexagonal nanoplates (PdSnNi NPs) alloy catalyst synthesized by a simple wet chemical method is reported for catalyzing formic acid oxidation, which greatly outperforms binary PdSn NPs and Pd/C catalysts, thanks to the synergistic effect of Pd, Sn, and Ni. With the assistance of octadecene and olamine system, a small-size hexagonal nanoplate morphology with high specific surface area was prepared. The electrochemical active area of PdSnNi NPs/C catalyst reaches 124.6 m 2 g −1 Pd , which is 9.5 times that of Pd/C catalyst. The mass activity of PdSnNi NPs/C reaches 2275.4 mA mg −1 Pd , which is 1.3 and 4.5 times that of PdSn NPs/C and Pd/C. Moreover, the stability of PdSnNi NPs/C catalyst is also greatly improved compared with PdSn NPs/C and Pd/C catalysts. It is worth noting that the PdSnNi NPs catalyst reduces the use of precious metal Pd, and the content of metal Pd only accounts for 46.42 % of the total content of metal, which effectively reduces the cost of the catalyst. The research results show that the introduction of Sn and Ni regulates the electronic structure of Pd, increases the active sites of the catalyst, and accelerates charge transfer rate, which lead to a significant improvement in the performance of the catalyst. In summary, this work proposes a novel and efficient Pd-based alloy catalyst for formic acid electrooxidation reaction.