A Time-Efficient and Safe Method for Scale-Up Synthesis of Highly Active Pt-Based Catalysts

Abstract

The carbon content acting as either a support or a protection layer is critical for the catalytic performance of Pt-based catalysts used for proton exchange membrane fuel cells. And, the highly active Pt-based catalysts often include an annealing process during the preparation. However, transferring fresh postannealed catalysts to air faces safety challenges since metal nanoparticles can catalyze the oxidation of the carbon content in the catalyst to generate a large amount of heat in a short time. The released heat, in turn, can raise the sample temperature and accelerate the oxidation reaction. Thus, to ensure processing safety and catalyst quality, the conventional method is complicated, time-consuming, and extreme-caution-required. Here, we report a simple and time-efficient method for transferring annealed catalysts to air together with the capability of optimizing the catalytic performance. With this method, we reduced the processing time from 180 to 10 min (saving 94.4%) without sacrificing the performance of prepared catalysts and achieved a scale-up preparation of up to 11 g per batch. Additionally, the prepared catalyst (PtCo/CB-60s-L_Pt) delivered a mass activity of 0.77 A/mg and a rated power of 12.8 W/mg, both of which are higher than the targets set by the United States Department of Energy. The achieved performance proved that the prepared catalyst is among the top-tier catalysts reported in practical fuel cell tests. Thus, the reported method is promising for reducing the process cost and guaranteeing the quality for industrial production of highly active catalysts.