Universal Surfactant-Free Strategy for Self-Standing 3D Tremella-Like Pd-M (M = Ag, Pb, and Au) Nanosheets for Superior Alcohols Electrocatalysis

Pd-based nanosheet materials have emerged as efficient catalysts for monobasic and polyhydric alcohol oxidation reactions. However, most reported synthetic methods of Pd-based nanosheets (NSs) are nonuniversal and surfactant-involved, leading to residue-covered surfaces with drastically damaged electrocatalytic properties. Herein, a universal, surfactant-free, simple one-pot route is developed for the precise synthesis of a kind of novel self-standing Pd-M (M = Ag, Pb, Au, Ga, Cu, Pt, etc.) NSs with tremella-like superstructures are assembled using ultrathin two-dimensional (2D) NSs. Benefiting from the universal surfactant-free methods, the obtained Pd-M NSs exhibit clean surfaces and stable three-dimensional (3D) self-standing structures that overcome the difficulty of normal close packing and overlapping 2D NSs. The Pd-M (M = Ag, Pb, and Au) NSs with tremella-like structures all show excellent ethanol oxidation reaction (EOR) and ethylene glycol oxidation reaction (EGOR) properties. In particular, with the optimal superstructure, better electronic effect, and promoted toxicity tolerance, the EOR/EGOR mass activities of Pd7Ag NSs, Pd7Pb NSs, and Pd7Au NSs are 8.2/7.3, 7.2/5.7, and 5.3/4.4 times higher than that of commercial Pd/C catalysts. This advanced 3D construction also endows Pd-M NSs with more favorable stability than Pd/C. This study may be extended to Pd-M (M = other metals) NSs and open up more opportunities for broad catalytic applications.