Liquid Metal Electrocatalyst with Ultralow Pt Loading for Ethanol Oxidation.

Abstract

Developing efficient and durable electrocatalysts for ethanol electro-oxidation is crucial for enabling the application of direct ethanol fuel cell technology. Herein, it is demonstrated that Pt-Ga liquid metal-based nanodroplets can serve as an efficient electrocatalyst to drive ethanol oxidation. The mass activity of Pt is significantly improved by alloying with liquid gallium. Guided by machine learning neural networks, a low-concentration alkaline electrolyte is specifically formulated to allow electrodes with ultralow Pt loading to demonstrate remarkable activity toward ethanol oxidation with a mass activity as high as 13.47 A mg^-1 _Pt, which is more than 14 times higher than that of commercial Pt/C electrocatalysts (i.e., 0.76 A mg^-1 _Pt). Computational studies reveal that the superior activity is associated with the presence of Ga oxides adjacent to Pt on the catalyst surface which leads to energetically favorable pathways for the oxidation process. The findings reveal untapped opportunities in the realm of liquid metal catalysis and hold great promise for the future development of high-performance alcohol fuel cells.