Ag-Cu bimetallic nanocatalysts for p-nitrophenol reduction using a green hydrogen source

The quest for new nanomaterials that can efficiently catalyze reduction reactions using green transfer hydrogenation process is an important current area of research. Conventionally, NaBH4, which is both expensive and toxic, has been the reducing agent for the model catalytic reduction of p-nitrophenol (Nip) to p-aminophenol (AP). The present communication studies the application of Ag-Cu bimetallic nanoparticles (Ag-Cu BNPs) stabilized by poly-vinylpyrollidone (PVP) as catalysts for this reaction with glycerol as the green hydrogen source. Bimetallic nanoparticles with different compositions were prepared using three different ratios (1:1, 2:1 and 4:1) of precursor silver and copper salts in appropriate amount of ethylene glycol and PVP. While the XRD patterns of these nanomaterials clearly show the formation of both pure silver and copper phases, the analysis of the data obtained from their LSPR and SEM EDX elemental mapping point to the formation of phase-separated nanostructures with adjacent Ag and Cu domains. The catalytic activity of these nanomaterials with glycerol and NaBH4 as the reducing agents are investigated. Catalytic activities of these bimetallic nanoparticles in terms of turnover frequency changes with composition variation. Synergistic catalytic activity with respect to composition was observed whether NaBH4 or glycerol was used as the reductant.