Fabrication of Au-Pd bimetallic dendrites and their catalytic application for 4-nitrophenol reduction

Bimetal nanocatalysts hold significant application potential in catalytic reactions due to their compositions, morphologies, and electronic structures. In the present work, a series of AuPd alloy dendrites were successfully prepared using sodium formate, without surfactants or templates. A systematic investigation was then conducted to analyze the composition of the AuPd bimetallic dendrites and the effects of preparation conditions on their structure and catalytic performance. The AuPd alloy dendrites were characterized through various techniques, including scanning electron microscopy, transmission electron microscopy, X-ray energy scattering spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results showed that the Au:Pd ratio in the AuPd alloy dendrites closely matched the initial feeding ratio. The catalytic activity and stability of the AuPd alloy dendrites towards 4-nitrophenol reduction were remarkably higher compared to those of the single metal Au and Pd nanocatalysts. Specifically, the Au₁Pd₁ alloy dendrites exhibited the highest catalytic reduction activity for 4-nitrophenol, with a reaction rate constant of 1.05 × 10^-2. Moreover, the stability of the Au₁Pd₁ alloy dendrites was also examined. The results demonstrated that the catalytic stability of the Au₁Pd₁ alloy dendrites did not experience a significant decrease even after five cycles of operation.