A robust triple-component electrocatalysts synthesis to improve the oxygen reduction reaction (ORR) is described. The electrocatalyst was prepared using a cost-effective “Suspension Unit for Reactive Evolution (SURE)” approach. The uniqueness of this SURE approach lies in the impregnation and hydrogen reduction to produce platinum nanoparticles (NPs) using a reduced graphene oxide (rGO). Morphological analyses of the electrocatalyst demonstrated uniform dispersion at 2nm Pt NPs with the size distribution of 1.76 ± 0.26 nm were uniformly deposited on the surface of rGO sheets. Using spectroscopy and electrochemistry analyzed it was determined that the rGO to FePc orientation was found to be at one phase of the composites only, based on the complete abolishment of Q and S bands from the ultraviolet spectroscopy. The mass activities of these Pt/FePc@rGO catalysts were superior (281.29 mA mgPt-1 at 0.86 V) when tested using a half-wave potential in an alkaline (KOH) system. Compared with commercial Pt/C catalysts, the Pt/FePc@rGO catalysts showed 2.8-fold higher in ORR current density under the same operating conditions, while the average Pt loading was about one-third of the commercial catalyst (Pt/C). The accelerated durability test (ADT) indicated the Pt/FePc@rGO catalysts showed about 8 mV decrease in voltage, corresponding to 2.5 mA cm-2 after 10,000 times 0-1.23V (vs. RHE) potential cycling; on the contrary, the Pt/C catalysts were subjected to much larger shift (53 mV). Methanol tolerance study also indicated the Pt/FePc@rGO showed an 2 mV shift, while the commercial Pt/C, 238 mV when an aliquot with 0.1 M methanol and 0.1M KOH aqueous electrolyte was added. The analyses indicated that the generated electrocatalyst exhibited enhanced electrocatalytic activity, robust anti-methanol poisoning property and long-term stability. Creativity of this study lies in cost-effective and feasible chemical synthesis (SURE) to produce multifunctional nano composites improve the ORR. This research opens a new paradigm to provide promising catalysts to advance their applications in direct methanol fuel cells and offers a rational strategy to design heterogeneous catalysts.

Improved oxygen reduction reaction using triple-component nanocatalysts

255th National Meeting (2018)

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