Catalysis of nanosized Pd metal catalyst deposited on Ti-containing zeolite by a photo-assisted deposition (PAD) method

Abstract

Using a photo-assisted deposition (PAD) method, nanosized Pd metal can be highly dispersed on Ti-containing silicalite zeolite (TS-1) under UV-light irradiation (PAD-Pd/TS-1). The nanosized Pd metal was deposited directly on the photo-excited tetrahedrally coordinated titanium oxide species (tetra-Ti-oxide) of TS-1 zeolite. Under the flow of H2 and O2 in water solvent, the efficient formation of H2O2 could be observed by the PAD-Pd/TS-1 catalyst under mild reaction conditions (ambient temperature and atmospheric pressure). Furthermore, the presence of phenol in this reaction system led to the formation of the products from the partial oxidation of phenol with the formed H2O2.

Application of Microwave-Assisted Deposition for the Synthesis of Noble Metal Particles on Ti-Containing Mesoporous Silica

“…We have previously developed a novel technique to synthesize nanosized metal particles on the isolated and tetrahedrally coordinated Ti-oxide moieties. The excited state of Tioxide moieties under UV-light irradiation act as anchor to deposit metal precursor such as Pt, Pd and Ag [27,28]. Along this line, we have found and herein wish to report that the Ti-containing mesoporous silica also act as a promising platform to deposit uniform and small metal particles under microwave irradiation (Scheme 1).…”

Applications of Single-site Photocatalysts to the Design of Unique Surface Functional Materials

“…Recently we have successfully utilized the single-site photocatalyst (Ti-containing zeolite (TS-1) and mesoporous silica (Ti-HMS)) as the platform for the synthesis of nano-size metal catalysts by the advanced photo-assisted deposition method. The nano-sized Pt, Pd metal and PdAu alloys can be synthesized using this technique [8,[33][34][35][36][37][38]. Under UV-light irradiation of the slurry of TS-1 zeolite in an aqueous PdCl 2 solution using a high-pressure Hg lamp at 295 K for 24 h, the Pd metal precursor species can be successfully deposited on the TS-1 (Pd/Ti = 0.6) [36].…”

“…The nano-sized Pt, Pd metal and PdAu alloys can be synthesized using this technique [8,[33][34][35][36][37][38]. Under UV-light irradiation of the slurry of TS-1 zeolite in an aqueous PdCl 2 solution using a high-pressure Hg lamp at 295 K for 24 h, the Pd metal precursor species can be successfully deposited on the TS-1 (Pd/Ti = 0.6) [36]. Similarly, Pt metal precursor species was deposited directly from an aqueous solution of H 2 PtCl 6 on the photo-excited tetrahedrally coordinated Ti oxide moieties of Ti-HMS mesoporous silica (Pt/Ti = 0.5) [33].…”

“…The nano-sized metal catalysts can be applied to the catalytic reactions with high efficiency [8,[33][34][35][36]. The PAD-Pt/Ti-HMS can exhibit the higher reactivity than the imp-Pt/HMS for CO oxidation reaction using a fixed-bet reactor.…”

“…Recently our research group has found that these singlesite photocatalysts can be used not only to promote the photocatalytic reaction but also to design the surface functional materials; nano-sized metal, alloy and binary oxide and hydrophilic transparent mesoporous thin film [33][34][35][36][37][38][39][40][41][42][43]. In this review, our recent applications of singlesite photocatalysts to the synthesis of the nano-sized metal catalysts, the visible-light sensitive binary oxide photocatalysts and the transparent mesoporous thin films as surface photo-functional materials are introduced.…”