Nanoparticle catalysts

In this review, the importance of nanoparticles (NPs), with emphasis on their general and specific properties, especially the high surface-to-volume ratio (A/V), in many technological and industrial applications is studied. Some physical and chemical preparation methods for growing several metallic and binary alloy NP catalysts are reviewed. The growth and mechanism of catalytic reactions for synthesis of 1D nanostructures such as ZnO nanowires and multiwall carbon nanotubes (MWCNTs) are discussed. Gas-phase production with emphasis on dependence of catalytic activity and selectivity on size, shape and structure of NPs is also investigated. Application of NP catalysts in several technological processes including H2 production and storage as well as antibacterial effect, gas sensors and fuel cells is discussed. The mechanism of H2 production from catalytic photoelectrochemical and photocatalytic degradation reactions of some organic dyes is discussed. Finally, the future outlook of NP catalysts in various disciplines is presented. (topical review)