The catalytic reduction of 4-nitrophenol to 4-aminophenol is a widely used model reaction for water treatment and to evaluate the catalytic activity of nanomaterials. Here, we report on the strong, yet overlooked, effect of cations in the borohydride-mediated reduction of 4-nitrophenol using gold as a catalyst. Catalytic activity consistently increases in the order Li+ + +, with KBH4 leading to the highest turnovers compared to LiBH4 or NaBH4, both with pre-formed gold nanoparticles but also using HAuCl4, AgNO3, or Pd(NO3)2.
Smolska et al. (Fri,) studied this question.