Preparation of Sub-5 nm Pt Nanotetrahedra Without Surfactant and Their Electrocatalytic Properties

Platinum catalysts with {111} surface has obvious advantages, but the control of {111} exposure usually requires surfactants which cover the surface and decrease the catalytic performance. In this paper, tetrahedral platinum nanoparticle catalysts were successfully prepared with a simple one-step hydrothermal method and their size were successfully controlled under sub-5 nm. The tetrahedral morphology was controlled through the decomposition of dimethylamine by DMF and the small size was determined by alcohol acid radical. Because of the profitable effect of the amines for the tetrahedral morphology, no surfactant was need during the preparation. The catalysis activity was assured by the tetrahedral morphology with Pt {111} exposure without the surfactant covering, and the small size further increased the number of activity sites. For HOR, the catalyst showed higher activity, stronger anti-CO poisoning performance and longer stability than those of commercial catalyst with the same platinum load. For ORR, the catalyst also showed better performances which further promoted the four-electron reaction. Our simple preparation method successfully achieved the aims of the morphology control, size control and the elimination of surfactant, which effectively assured the good catalyst performances. The simple preparation path of such good catalysts shows a great application potential. Graphical Abstract