Plasma synthesis of Pt/C catalysts and their electrocatalytic performance

Abstract A simple, green, and scalable approach, utilizing dielectric barrier discharge (DBD) plasma in lieu of chemical reductants, is presented for producing Pt/C catalysts. The results revealed crystalline well-dispersed Pt nanoparticles (PtNPs) of small sizes were generated on the surface of carbon support, where the Pt loading can be regulated by adjusting the H2PtCl6 concentration. The resulting Pt/C catalysts demonstrated excellent catalytic activity in both acidic and alkaline electrolytes for hydrogen evolution reactions (HER) and methanol oxidation reactions (MOR). With the rise of the Pt loading, the catalytic activity gradually improves. Specifically, for HER, an overpotential value of 120 mV was measured for the 8 wt% Pt/C-modified electrode at a geometric current density of -10 mA/cm2, with a Tafel slope of 45.4 mV/dec in acidic electrolyte. The values became 208 mV and 83.7 mV/dec in alkaline electrolyte. Same phenomenon was also observed in MOR, where the increase of the Pt loading results in faster electron transport rate and stronger methanol oxidation peak. Besides, the catalytic activity of the plasma-prepared Pt/C catalysts is better than the commercial samples with the same Pt loading. This work demonstrates a DBD plasma-assisted strategy for the preparation of Pt/C catalysts in an efficient and environmentally friendly manner.