Fabrication and characterizations of PdAu/thiolation poly (phthalazinone ether ketone) superfine fibrous membrane as a free-standing electrocatalyst for methanol oxidation

Thiolation poly (phthalazinone ether ketone) (PPEK-SH) superfine fibrous membrane (SFM) was successfully fabricated via grafting and electrospinning. The PPEK-SH SFM exhibited high glass transition temperature (314.9 °C), robust tensile strength (14.74 MPa) and high porosity (80.2%), which were critical advantages for the SFM as plating template applied in fuel cells. Au nanoparticles (NPs) were assembled on the SFM as seeds, and then Pd NPs were deposited on the membrane by electroless plating. Characterization with scanning electron microscopy (SEM), energy-dispersive spectrometry (EDX), transmission electron microscopy (TEM) and X-ray diffraction (XRD) indicated that the surface of PPEK-SH fibers was almost fully covered by a thick Pd layer. The PdAu/PPEK-SH SFM inherited the properties of PPEK-SH and conductivity of Pd, thereby was successfully used as a free-standing electrocatalyst towards methanol oxidation without resorting to any conductive support. More importantly, benefiting from the introduction of -SH for anchoring noble metal NPs, the electrocatalyst presented a good stability. The peak current density reduced just 18.7% after 500 cycles, which would meet the needs of long-term use. This work may provide a new approach for the development of free-standing electrocatalyst based on electrospun nanofibers.