Poly(2,5-dimethoxyaniline-co-2,5-diaminobenzenesulfonic acid) with cross-linking structure for platinum deposits in methanol oxidation

Cross-linking structural copolymer, poly(2,5-dimethoxyaniline-co-2,5-diaminobenzenesulphonic acid) was synthesized by electrochemical deposition of two monomer, 2,5-dimethoxyaniline, DMA and 2,5-diaminobenzenesulfonic acid, DABSA. The cross-linking structure of copolymer was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric techniques. Copolymer with cross-linking structure provides more and deeper nucleation sites for the deposition of platinum (Pt) than homopolymer via electrochemical method, being certified by secondary ion mass spectrometer. Meanwhile, the existence of the SO₃H group in copolymer might also help the electrodeposition of Pt. Copolymer-Pt nanocomposite film demonstrates better activity and stability toward methanol oxidation than homopolymer-Pt.