Platinum-group-metal (PGM) based catalysts are still mandatory for catalyzing the sluggish oxygen reduction reaction (ORR) in practical proton exchange membrane fuel cells. Significant performance improvement compared with commercial Pt/C catalyst in device is required to cut down stack cost, since the catalyst account for ≈50% of the projected total cost for large-scale production.A promising strategy is partially replacing Pt with low-cost transition metals (e.g. Co, Ni) and designing alloy catalysts with enhanced catalytic performance than pure Pt catalysts.In the last few decades, PGM based nanocrystals with controlled particle size, shape, composition and morphology have shown significant performance improvement (vs. Pt/C). However, the lack of robust process for nanocatalysts manufacturing significantly hinder their real-world application.
In this presentation, we will discuss the use of flow reactor for large-scale manufacturing of size and composition controlled PtCo_xNi_y catalysts. We systematically studied the synthesis with various Co and Ni contents. Both small-angle X-ray scattering and transmission electron microscopy (TEM) results revealed that the produced PtCo_xNi_y nanoparticles have uniform size and dispersed on the conductive substrates uniformly (Figure 1). Electrochemical activity results have shown that the PtCo_xNi_y catalysts synthesized in this work delivered substantially improved performance for ORR than commercial Pt/C catalysts.

<b>Figure 1</b>. Comparison of TEM images of PtCo<sub>x</sub>Ni<sub>y</sub> catalysts produced with a) a flow reactor, and b) a batch flask reactor.

Figure 1. Comparison of TEM images of PtCo_xNi_y catalysts produced with a) a flow reactor, and b) a batch flask reactor.

Bomin Li

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