Efficient and green electrochemical synthesis of 4-aminophenol using porous Au micropillars

The development of new, efficient, chemoselective, and seemingly stable catalysts to rapidly convert 4-nitrophenol into 4-aminophenol, which is a particularly valuable chemical within multiple industries, is highly required. The use of non-toxic and non-corrosive chemicals for 4-aminophenol synthesis presents further challenges. We show a simple and scalable shape-controlled electrodeposition using a dual-template method for the synthesis of well-defined porous Au micropillar array electrodes to enhance electrocatalyst stability, efficiency, and durability during the electroreduction of 4-nitrophenol. Consequently, we avoid the use of toxic and aggressive chemical reducing agents and minimize the production of residues. Surface areas up to 55.2 m2 g−1 are achieved, which represent a substantial improvement over non-architectured Au film electrodes. Porous Au micropillars exhibit excellent yields (̴100 %), chemoselectivity (other byproducts are not detected), and a high kinetic constant of 2.5 × 10-2 min−1, which is impressively higher than those reported recently for Au thin films or Au-based electrocatalysts.