The synthesis of PtCu/C catalyst with a hollow sphere structure by chlorine-free platinum precursor for the oxygen reduction reaction

The frequently used chloroplatinic acid or other Pt precursors containing Cl element during the preparation process of Pt-based catalysts lead to catalyst poisoning and instability. In this work, a chlorine-free PtCu(N)/C R-F catalyst with a hollow sphere structure was successfully synthesized by employing [Pt(NH 3 ) 4 ](OH) 2 and [Cu(NH 3 ) 4 ](OH) 2 as the chlorine-free metal precursors, which using the strong electrostatic adsorption (SEA) between positively charged metal precursor ions and the negatively charged oxygen-containing functional groups (OCFGs) on the carbon support (C R-F ) and combined with the impregnation reduction method. Compared to commercial Pt/C, the experimental results show that the PtCu(N)/C R-F catalyst, displays better ORR performance under acidic condition, the onset and half-wave potentials are 0.961 V (vs. RHE) and 0.827 V (vs. RHE), respectively. Furthermore, it also shows a significant performance advantage in a gas diffusion electrode (GDE) half-cell. Density-functional theory (DFT) calculations show that the introduction of Cu has adjusted the electronic structure of Pt, weakened the adsorption of oxygen-containing intermediates, and ultimately enhanced the catalytic activity and stability of ORR. This work presents a simple and efficient method for preparing chlorine-free Pt-based catalysts.