The effect of NaOH in the formation PtNi/C nanocatalyst for cathode of PEMFC

PtNi/C alloy nanocatalysts were successfully synthesized by refluxing a polyol solution with platinum (Pt) and nickel (Ni) salt with different NaOH volumes. The strategy of the enhancement of cathode performance in Proton Exchange Membrane Fuel Cell (PEMFC) is the use of custom nanocatalysts that could improve the macroscopic kinetics rate of the Oxygen Reduction Reaction (ORR). In this study, development of polyol reduction method of depositioning simultaneously Pt and Ni in carbon surface while hindering the agglomerations of alloy particles was carried out. The prepared catalyst was characterized by X-Ray Diffraction (XRD), Energy Dispersive X-ray (EDX) analysis and selective chemisorptions. The results show that the diffraction pattern of crystallites changes when the content of NaOH varies. XRD patterns show disorder structure of face cubic centre (fee) with particle size around 5 nm. From EDS analyses, PtNi compositions on carbon from the sample are around 29% and hydrogen adsorption on Pt atom that is showed on the nanocatalyst surface is approximately also 29%. Activity of the carbon-supported PtNi catalyst for oxygen reduction reaction was tested by Cyclic Voltammetiy (CV) at 900 mV vs. RHE in IM HC10₄. The resulted ESA is around 37 cm²/mgPt and specific activity (SA) is 99 μA cm^-2. The result shows that PtNi/C of NaOH 5 mL sample provides SA that is three times as high in comparison to commercial Pt/C catalyst.