Progress in design and architecture of metal nanoparticles for catalytic applications. 
Over the past few years, nanometer-sized transition metal particles have been intensively pursued as potentially advanced catalysts because their special properties lie between those of single metal atoms and bulk metal.  Achieving the accurate control of particle size and overall particle size distribution is one of the most crucial challenges to provide unique chemical and physical properties.  We highlight herein our recent progress in the exploitation of promising nanoparticle (NP)-based catalysts designed by precise architecture that enable efficient and selective chemical transformations and can be completely separated and are recyclable.  This perspective article consists of the following two specific topics: (i) multifunctional catalysts based on magnetic NPs and (ii) new routes for the preparation of supported metal NPs catalysts.  The synthetic strategies described here are simple and general for practical catalyst design, thus allowing a strong protocol for creating various nanostructured catalysts.