Intermetallic Co-Pt/C Nanoparticles Synthesized Via Sonochemical Method As Enhanced Electrocatalysts for Cathode of PEMFC

摘要

For fuel cell stack of 80 kW, platinum for electrocatalyst requires around 10 g per fuel cell electric vehicle (FCEV). A large-scale synthesis method for the low-platinum catalyst is necessary for this field to reduce man-power. Ultrasound-assisted polyol synthesis (UPS) is a method for the preparation of small and uniform size transition metal core-platinum shell nanoparticles evenly distributed on the support. Platinum(II) acetylacetonate, Cobalt(II) acetylacetonate, and carbon support were dispersed in ethylene glycol which is reducing agent and irradiated by ultrasound for 3 h to reduce the precursor to metal nanoparticles, followed by washing and drying to obtain a powder. The characterization was observed by solution color visualization, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and electrocatalytic performance. Also, the synthesized samples were calcined at various temperatures to cause the atomic rearrangement to the most stable arrangement, and atomic accumulation of boundary between each atom and compression of platinum lattice that affects activity or durability of electrocatalyst has changed. Synthesized sample with optimized synthesis and treatment condition shows improved electrochemically active surface area (ECSA) and Oxygen reduction reaction (ORR) catalytic activity in the half-cell test and durable catalytic activity in the performance evaluation of membrane-electrode assembly (MEA) compared to existing Platinum catalyst. As renewable energy conversion and storage system is one of the main challenges, FCEV is developed to solve pollution from CO_2 emission and oil depletion issues. Our low-platinum nanoparticle with uniform distribution synthesized using a sonochemical method will replace precious metal catalysts used in fuel cells instead of platinum catalysts.