Ternary N, S, and P-Doped Hollow Carbon Spheres Derived from Polyphosphazene as Pd Supports for Ethanol Oxidation Reaction

Ethanol oxidation reaction (EOR) is an important electrode reaction in ethanol fuel cells. However, there are many problems with commercial ethanol oxidation electrocatalysts today, such as poor durability, poor anti-CO poisoning ability, and low selectivity for C-C bond cleavage. Therefore, it is very meaningful to develop a high-performance EOR catalyst. Herein, we designed ternary N, S, and P-doped hollow carbon spheres (C-N,P,S) from polyphosphazene (PCCP) as Pd supports for EOR. Using SiO2 spheres as the templates, the PCCP was first coated on the surfaces of SiO2 spheres by in situ polymerization. Through high-temperature pyrolysis and hydrofluoric acid-etching, the hollow PCCP has a large surface area and porous structure. After loading Pd nanoparticles (NPs), the Pd/C-N, P, S catalysts with Pd NPs decorated on the surfaces of C-N, P, S can achieve a high mass peak current density of 1686 mA mg(Pd)(-1), which was 2.8 times greater than that of Pd/C. Meanwhile, the Pd/C-N, P, S catalyst also shows a better stability than that of Pd/C after a durability test of 3600s.