Mesostructural Engineering of Faceted Gold Nanoparticles in 3D KIT‐6 Silica for Enhanced Catalytic Efficiency
Sudipta Ghosh, Manajit Mandal, Shyamal Mondal, Bipattaran Paramanik, Arpan Dutta, Manasi Mukhopadhyay, Prasanta Kumar Sinha, Prakash Chandra MondalABSTRACT
Gold nanoparticles (Au NPs) supported on ordered mesoporous silica have attracted significant attention as robust nanocatalysts. In this study, high‐gold‐content three‐dimensional (3D) mesoporous silica (KIT‐6‐Au NPs) was synthesized, which exhibited a 3D cubic Ia3d mesostructure with uniformly dispersed Au NPs (∼8 nm) predominantly exposing the (111) facets. Structural analyses were conducted by Brunauer–Emmett–Teller surface area measurement, Raman spectroscopy, solid‐state Si 29 NMR spectroscopy, Transmission electron microscopy, x‐ray diffraction, x‐ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectroscopy, confirming high gold loading 15.5 wt% and strong metal–support interaction. Catalytic performance was evaluated through the reduction of 4‐nitrophenol (4‐NP) with NaBH 4 as a model reaction, exhibiting a maximum apparent rate constant of 0.0086 ± 0.0002 s − 1 at 25°C. It surpasses comparable Au–mesoporous silica systems and is competitive with other silica‐supported metallic nanocatalysts. The findings further confirm that the reduction of 4‐NP by NaBH 4 in the presence of the KIT‐6‐Au NP catalyst proceeds via a heterogeneous catalytic pathway and that the catalyst is structurally robust under the reaction conditions. This work highlights the potential of facet‐engineered, high‐loading Au NPs integrated within a 3D mesoporous silica framework as an efficient catalyst capable of promoting diverse reactions under mild conditions.