Constructing efficient ternary PtTeCu nano-catalysts with 2D ultrathin-sheet structures for oxidation reaction of alcohols

Abstract

Ternary Pt-based nanomaterials have arisen much interest due to their outstanding electro-catalytic performance to reactions in fuel cells as well as the decrease of the utilization of Pt atoms. The construction of two-dimensional (2D) ternary Pt-based nanocatalysts by combining the advantages of alloy and geometric structure were appealing. In this work, we prepared free-standing ultrathin and highly flexible PtTeCu nanosheets (NSs) by a one-pot polyol method. The ultrathin feature and nanopore structure at the edges allowed the exposure of a large number of Pt atoms, supplying sufficient active sites for the catalytic reaction. The obtained PtTeCu NSs exhibited significantly higher ethylene glycol oxidation reaction (EGOR) and methanol oxidation reaction (MOR) performance reaching mass activities of 7.1 A/mg and 4.9 A/mg, compared to 6.5 and 6.1 times that of commercial Pt/C, respectively. The freestanding PtTeCu NS were subjected to long-term stability tests (200 cycles) where activity decay and structural changes were negligible. DFT calculations showed that the introduction of Cu and Te into Pt resulted in a significant downward shift of the d-band center of Pt. This weakened the adsorption energy of the products on PtTeCu NSs and accelerated the desorption of the products to the catalyst surface, enhancing the catalyst activity and stability. The unique ultrathin nano-sheet structures could provide sufficient active sites for the catalytic reaction, which also contributed to the excellent catalytic performance.