A modified deposition precipitation (DP) method has been developed to address a fundamental issue of supporting well dispersed Au nanoparticles on silica.

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The encapsulation of gold nanoparticles 8–12 nm in size within a porous Ti–SiO2 shell to form a core–shell nanoarchitecture was investigated, and the catalytic activity of the resulting structure was probed. Detailed characterization of the synthesized materials shows that the core–shell morphology is lost beyond a certain amount of incorporated titanium, and results in normal gold‐supported Ti–SiO2. The material has a high surface area (913 m2 g−1) and high porosity, both of which make it an excellent choice for catalytic applications. With the optimum amount of incorporated Ti, the core–shell catalyst shows excellent room‐temperature CO oxidation activity over several cycles with retention of its morphology at higher temperatures.

Small gold nanoparticles of size less than 5 nm encapsulated inside titanium modified silica shell have been reported. Here, a modified sol–gel method, which is a one-step process, produces Au@Ti–SiO2 nanocatalyst with a good control of titanium loading. With a titanium loading of 0.9 and 2.2 wt % in silica, unprecedented low temperature activity (full conversion) is observed for this catalyst for CO oxidation reaction compared to Au@SiO2 catalyst. A combination of optimum sized gold nanoparticles with a large amount of oxygen vacancies created due to Ti incorporation in silica matrix is considered to be the reason for this enhanced catalytic activity. The size of gold nanoparticles is maintained even after high temperature pretreatments, which show the benefit of encapsulation. The effect of the various pretreatments on the catalytic activity has also been reported.