AMH participated in the monitoring of the experimental work, data analysis, discussion, and revision of the manuscript. All authors read and approved the selleck inhibitor final manuscript.”
“Background Supported transition metal nanoparticles are widely used as catalysts and electrocatalysts in many industrial applications. Carbon-based electrically conducting supports are frequently used in the low-temperature proton exchange membrane fuel cells, while the refractory metal-oxide supports are used in moderate- and high-temperature applications such as automotive catalytic converters. Platinum is one of the most commonly used catalysts. Studies with single crystals

[1] showed that catalyst activity can be influenced by the atomic arrangement of the catalyst surface as well as the presence of the defect sites. In the case of nanoparticulate catalysts, the shape can be an important governing factor in overall catalyst activity [2] because the nanoparticle shape is dictated by the crystallography of facets with the lowest surface energy. Each

facet can have different specific catalytic activities. Particle-substrate interface crystallography and interfacial energy are an additional shape-controlling factor of supported catalysts [3]. The ability to fabricate well-defined model systems on various substrates where one can systematically vary the size, shape, and spacing between nanoparticles is of high fundamental [4] and practical importance [5]. Nanofabricated supported model catalyst systems can be probed Alpelisib ic50 with traditional scanning probe imaging find more techniques and synchrotron X-ray surface characterization tools.

In the past, top-down nanofabrication techniques such as electron beam lithography (EBL) have been successfully used to produce platinum catalyst arrays [2, 6, 7]. Expensive instrumentation and multistep pattern transfer procedures make production of these systems challenging and costly. Additionally, EBL is a rather slow serial technique, acetylcholine and patterning of several square millimeters of the substrate area with densely packed arrays of dots can take many hours. For the practical applications, e.g., fuel cells, the total catalyst area has to be in the order of hundreds of square meters. There is clearly a motivation to produce well-defined catalyst samples supported on various substrates using cheaper and faster techniques. Natural lithography [8] alone or in combination with other techniques has been successfully used to produce metallic nanostructures and nanoparticle crystallites of random shape [9] and orientation [10]. The purpose of this report is to present a simple two-step process based on mask templates of a self-assembled silica colloidal sphere monolayer suitable for production of epitaxially oriented platinum nanoparticle arrays with precisely controlled shape.