Reversible ionic liquids (RevILs) for the preparation of thermally stable SBA-15 supported gold nanoparticle catalysts

Reversible ionic liquids (RevILs) are ionic liquids that can be switched between molecular and ionic forms via two stimuli, and they can assist in the synthesis of colloidal gold nanoparticles. The RevIL-stabilized gold nanoparticles are deposited in the pores of SBA-15 mesoporous silica via incipient wetness without the functionalization of the SBA-15 surface. The location of nanoparticles inside the pores was confirmed by transmission electron microscopy technique and by a measured increase in the thermal stability of the nanoparticles in SBA-15 compared to non-porous silica. The porous gold catalysts are active in the selective oxidation of benzyl alcohol without calcination due to the absence of the ligands on the gold surface after deposition. Additionally, they are more active than the non-porous gold catalysts, indicating that the pore geometry enhances catalytic performance. Ultimately, the catalysts prepared by RevIL technique are thermally stable and active and show fine control over particle size. [Display omitted] •Au nanoparticles supported on SBA-15 were prepared using reversible ionic liquids.•Nanoparticle deposition in mesopores is achieved without modifying the surface.•The elimination of calcination allows for improved control over particle size.•The as-synthesized catalysts are active in the selective oxidation reaction.