Low-temperature CO oxidation on Au/fumed SiO₂-based catalysts prepared from Au(en)₂Cl₃ precursor

Many gold catalysts have been actively surveyed, but Au/SiO₂ catalysts that are highly active for CO oxidation still remain evasive. In this work, gold nanoparticles well dispersed on Cab-O-Sil fumed SiO₂ were prepared using Au(en)₂Cl₃ (en = ethylenediamine) as the precursor, and found to be very active for CO oxidation below 0 °C. The catalyst pretreatment via reduction and calcination, effect of gold loading, post-treatment in acidic and basic media, catalyst deactivation, storage, regeneration, and effect of surface modification by other metal oxides were explored. The results provide new perspective on the activation and promotion of active Au/SiO₂-based catalysts.