Phase engineering of Pd–Te nanoplates via potential energy trapping

Abstract

Phase modulation of noble metal alloys (NMAs) is critically important in nanoscience since the distinct atomic arrangements can largely determine their physicochemical properties. However, the precise modulation of NMAs is formidably challenging, because thermodynamically stable phases are generally preferential compared to those metastable ones. Herein, we proposed a potential energy trapping strategy for phase modulation of Pd–Te alloys with solvents. Thereinto, ethylene glycol can increase the energy barrier for both Pd leaching and Te introduction, forming metastable Pd₂₀Te₇ phase. Inversely, N, N-dimethylformamide is unable to trap metastable phase, inducing the phase evolution to thermodynamically stable PdTe phase, and the precise phase modulation was realized including Pd₂₀Te₇, PdTe and PdTe₂ phases. The Pd–Te alloys displayed phase-dependent formic acid oxidation catalytic performance with PdTe phase showing the best. This work proposes a strategy for creating metastable phase with potential energy trap, which may deepen the understanding of phase engineering for noble metal-based nanocrystals.