Synthesis of Highly Active and Thermally Stable Nanostructured Pt/Clay Materials by Clay-Mediatedin SituReduction

Abstract

Novel and intriguing one-pot in situ method for the preparation of nanostructured Pt-clay materials under simple conditions is reported. In this synthesis, an inorganic clay mineral such as synthetic hectorite ("Laponite XLG") or natural montmorillonite ("Kunipia F") serves as a mild and effective reducing agent for Pt ions, which is uncommon for such a clay system, and also acts as an outstanding stabilizer for the resulting Pt nanoparticles. In aqueous solution, exfoliated colloidal clay platelets forms complex with Pt ions in the initial stage of mixing. Devoid of any organic dispersants or external reducing agents, subsequently, the Pt nanoparticles (3-6 nm) generated by clay-assisted in situ reduction of Pt ions successfully anchored onto the clay nanoplatelets. The Pt-clay material features a very high surface area (312 m(2) g(-1)) and has excellent catalytic activity, as was kinetically evaluated via the reduction of 4-nitrophenol with NaBH(4). After drying, this remarkably stable nanocomposite is completely redispersible in water and displays extreme thermal stability (up to 500 °C). On the basis of these results, this synthetic strategy is anticipated to be a very simple, economical, and green approach for the synthesis of nanostructured Pt-clay materials.

Palladium nanoparticles deposited on silanized halloysite nanotubes: synthesis, characterization and enhanced catalytic property

“…Precious metals nanoparticles on catalyst supports have attracted considerable interest because they have been used in a number of catalysis applications, including transformation of organic12345 and fuel cells67891011. Reports indicate that the catalytic performance could be greatly enhanced by nanotube supports.…”

Enhanced Catalytic Activity of Platinum Nanoparticles by Exfoliated Metal Hydroxide Nanosheets

“…As the ex‐LDH–Pt possesses the same amount of Pt as the free Pt NPs, this is dominantly ascribed to the partially blocked surfaces of immobilized Pt NPs by the LDH nanosheet, which leads to less‐accessible surfaces for the diffusion of reactants than in the case of the free Pt NPs. Importantly, the ex‐LDH–Pt exhibited more competitive catalytic activity than other supported Pt catalysts (clay/Pt,20d TOF=0.1 min −1 ; CNT/Pt,20b TOF=0.67 min −1 ) toward the reduction of p ‐nitrophenol.…”

Catalytic hydrodenitrogenation of propionitrile over supported nickel phosphide catalysts as a model reaction for the transformation of pyrolysis oil obtained from animal by-products

“…(1) and (2) [34], the latter two of which are not present on the silica support and probably responsible for the stronger adsorption of the intermediates. These adsorption sites are most probably lead to the basic character of Laponite surface [35]. The higher surface concentration of unsaturated intermediates is related to their longer lifetime over Ni 2 P/L catalyst relatively to the silica supported catalysts, which probably also explains the higher relative concentration of tertiary amine to lower amines.…”