Indium-doped flower-shaped PdIn nanocatalysts for enhanced ethanol oxidation

Abstract

Palladium nanocatalysts with a three-dimensional structure show excellent catalytic efficiency because more atoms are exposed on the surface to participate in the reaction. And doping three-dimensional palladium nanocatalysts can further improve their catalytic performance. However, it is a challenge to dope other atoms precisely while maintaining the three-dimensional structure. In this work, three-dimensional flower-shaped PdIn nanocatalysts with different doping contents of indium atoms were synthesized by a one-step reaction in liquid phase reduction. The addition of indium atoms not only plays an important role in maintaining the three-dimensional flower structure, but also effectively regulates the composition of palladium nanocatalyst. The indium-doped three-dimensional flower-shaped PdIn nanocatalysts show enhanced catalytic efficiency in the ethanol oxidation reaction. And the PdIn_0.024 catalyst exhibits the best mass activity (2380 mA mg_Pd⁻¹) and specific activity (10.51 mA cm⁻²), which are 3.98-fold and 4.17-fold higher than those of the commercial Pd/C nanocatalyst. These enhanced properties are from the regulation of the electronic structure of palladium by indium atoms and the three-dimensional flower-shaped nanostructure. The results show that the catalytic efficiency of palladium in ethanol oxidation can be improved effectively by doping indium atoms and precisely regulating the composition of palladium nanocatalysts with a three-dimensional flower shape.