(560fn) Catalytic Oxidation of Volatile Organic Components (VOCs) over Silver Nanoparticles Dispersed in Monodisperse Titania Nanospheres

Volatile Organic Compounds (VOCs) are a class of organic chemicals with high vapor pressure at room temperature. They are emitted from a variety of sources and it is crucially important to treat them properly in order to avoid potential environmental and health issues. Complete oxidation of these VOCs to CO₂ and water at low temperatures with the aid of a suitable catalyst is a promising way to reduce the risks associated with VOCs. Recent developments in the field of catalysis have facilitated some interesting advancements in catalysis architecture. One such development is encapsulating the active metal by a metal oxide nanostructure. This morphology, while helping maintain a constant size distribution, also promotes strong metal-support interactions by maximizing the number of interstitial sites. However, the synthesis of encapsulated catalysts is often complicated and results in an inconsistent yield, which has hindered extensive research using this architecture. In the present study, a simple, one-pot and scalable synthesis of Ag nanoparticles dispersed in mesoporous TiO₂ nanosphere has been explored by controlling the hydrolysis and condensation rates of TiO₂ precursor in a mixture of water and alcohol at room temperature. The method offers independent tunability of the size of silver nanoparticle and the TiO₂ mesopores. These catalysts have been characterized by several physicochemical techniques: XRD, N₂ adsorption, TPR, XPS, HR-TEM, SAED and EDX. The activity of the synthesized catalyst was tested by conducting oxidation reactions of n-butanol. Under n-butanol: oxygen molar ratio of 1:500 and space velocity of 240000 ml g^-1h^-1, n-butanol was completely oxidized into CO₂ and H₂O at 210⁰C over the 50mg catalyst. The intimate contact between the silver and Titania at the interface makes these materials an interesting candidate for low temperature VOC oxidation. Due to high efficiency, good stability, low cost, and ease of preparation, Silver dispersed in TiO₂ nanosphere is a promising catalyst for the practical removal of volatile organic compounds.