Effect of Morphology of Platinum Nanoparticles on Benzene Oxidation Activity.

Abstract

The effect of morphology of Platinum (Pt) nanoparticles supported on alumina (γ-Al2O3) for complete catalytic oxidation of volatile organic compounds (VOCs) was investigated. Pt nanoparticles were synthesized through a simple method comprising of reduction followed by calcination of metal precursor coated chitosan templates using three different reducing agents: sodium borohydride (NaBH4), hydrazine (N2H4) and hydrogen (H2). The morphology and facet orientation of Pt nanoparticles were influenced by the reducing agents. The catalytic oxidation performance studies of these Pt nanoparticles loaded on γ-Al2O3 for VOCs showed strong dependence of their activities on their morphologies. High indexed facet (220) Pt nanosheets synthesized through NaBH4 reduction showed superior catalytic oxidation activity compared to the catalysts prepared using other reducing agents. Cyclic performance studies on these catalysts showed stable benzene oxidation performance implying their thermal stability. The absence of any shape directing agents in the synthesis of Pt nanoparticles with homogeneous morphologies and preferential orientation is an aspect that can be extended to other catalytic applications.