Morphology-dependent selective hydrogenation catalysis of hollow AuCu bimetallic nanostructures

Abstract

We synthesized hollow AuCu bimetallic nanostructures using a Cu2O template and evaluated their hydrogen dissociation performance. The formation of a superstructural bimetallic and well-inherited shape was confirmed using transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The AuCu bimetallic nanostructures were tested for the catalytic reduction of o-nitroaniline to 1,2-benzenediamine, and they showed much better catalytic activity than pure Au. The hollow AuCu cubic structure exhibited superior catalytic efficiency (reaction rate constant=0.33min−1) compared with other structures such as a cuboctahedral structure (0.08min−1), an octahedral structure (0.17min−1), and pure Au (0.06min−1). Furthermore, we examined the dependence of o-nitroaniline reduction activity of the hollow AuCu hybrids on NaBH4 concentration. The reaction rate constant became saturated at a lower NaBH4 concentration for Au nanoparticles, while its saturation occurred at a higher NaBH4 concentration in the case of hollow AuCu nanostructures.