Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging. Herein, using visible light, a class of quaternary PtAgBiTe ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel cells. The modified electronic structure of Pt, enhanced hydroxyl adsorption, and abundant exterior defects afford Pt1Ag0.1Bi0.16Te0.29/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells, and the corresponding peak power density of Pt1Ag0.1Bi0.16Te0.29/C is respectively 129.7, 142.3, 105.4, 124.3, and 128.0 mW cm−2, considerably outperforming Pt/C. Operando in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt1Ag0.1Bi0.16Te0.29/C occurs via a CO-free direct pathway. Density functional theory calculations show that the presence of Ag, Bi, and Te in Pt1Ag0.1Bi0.16Te0.29 suppresses CO* formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H2O dissociation to improve electrocatalytic performance. This synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets (from ternary to octonary nanosheets), and efficiently capture precious metals (i.e., Pd, Pt, Rh, Ru, Au, and Ag) from different water sources.