A unique ordering effect has been observed in functional catalytic nanoscale materials. Instead of randomly arranged binding to the catalyst surface, metal nanoparticles show spatially ordered behavior resulting in formation of geometrical patterns. Understanding of such nanoscale materials and analysis of corresponding microscopy images will never be comprehensive without appropriate reference datasets. Here we describe the first dataset of electron microscopy images comprising individual nanoparticles which undergo ordering on a surface towards the formation of geometrical patterns. The dataset developed in this study spans three levels of nanoscale organization: (i) individual nanoparticles (1-5 nm) and arrays of nanoparticles (5-20 nm), (ii) ordering effects (20-200 nm) and (iii) complex patterns (from nm to μm scales). The described dataset for the first time provides a possibility for the development of machine learning algorithms to study the unique phenomena of nanoparticles ordering and hierarchical organization.

Metal on carbon catalysts (M/C) are ubiquitously used in modern research and industry to carry out a variety of chemical transformations. Stable metal-support frameworks and inertness of the carbon materials are usually taken for granted in these very useful catalytic systems. Initially, the present study was aimed to increase the efficiency of Pd/C and Pt/C catalytic systems under microwave and conventional heating. Interestingly, a dynamic behavior of the metal nanoparticles was revealed, and a series of carbon support transformations occurred during the thermal treatments of the catalysts. Microwave and thermal heating of the M/C catalysts resulted in substantial transformations of the carbon supports via the formation of pits, trenches, nanofibers, and nanowalls. Detailed studies with field-emission scanning electron microscopy were carried out involving statistical averaging over large surface areas. The effects of the dynamic behaviors of the supported metal particles on the catalytic activities of the synthetically useful Mizoroki-Heck and Suzuki-Miyaura reactions were demonstrated. Revealed dynamic behavior and modification of the carbon support due to microwave treatment were observed in a number of M/C systems (M = Pd, Pt, Ni, Co, Cu, Fe, and Au).

Defectiveness of carbon material surface is a key issue for many applications. Pd-nanoparticle SEM imaging was used to highlight “hidden” defects and analyzed by neural networks to solve order/disorder classification and defect segmentation tasks.

In recent years, the application of microwave (MW) irradiation has played an increasingly important role in the synthesis and development of high performance nanoscale catalytic systems. However, the interaction of microwave irradiation with solid catalytic materials and nanosized structures remains a poorly studied topic. In this paper we carried out a systematic study of changes in morphology under the influence of microwave irradiation on nanoscale particles of various metals and composite particles, including oxides, carbides, and neat metal systems. All systems were studied in the native solid form without a solvent added. Intensive absorption of microwave radiation was observed for many samples, which in turn resulted in strong heating of the samples and changes in their chemical structure and morphology. A comparison of two very popular catalytic materials—metal particles (M) and supported metal on carbon (M/C) systems—revealed a principal difference in their behavior under microwave irradiation. The presence of carbon support influences the heating mechanism; the interaction of substances with the support during the heating is largely determined by heat transfer from the carbon. Etching of the carbon surface, involving the formation of trenches and pits on the surface of the carbon support, were observed for various types of the investigated nanoparticles.