N-doped carbon materials are used across a wide range of energy applications including fuel cell catalysts, CO₂ electroreduction, catalyst supports, and energy storage materials. They are often integrated with metals in the form of either metal nanoparticles or atomically-dispersed sites to tune their performance for specific catalytic reactions. In general, these materials are very heterogeneous, containing a multitude of nitrogen functionalities and consequently, they are intrinsically challenging to understand. Therefore, elucidating the effects of nitrogen dopants on nucleation and stability of metals across the periodic table calls for close collaboration between theoretical and experimental studies, a further development of characterization approaches.

This talk addresses these challenges by studying two families of catalysts derived from a series of N-doped carbon nanospheres. N-doped nanospheres are synthesized solvothermally with the ability to control size, shape, concentration of nitrogen dopants, and their nitrogen functionalities. The tunability of these spheres allows for systematic studies that help to identify trends with different N functionalities and densities. First set of studies investigates metal adsorption trends observed across periodic table. The trends observed with DFT are compared to experimental results obtained with Scanning Transmission Electron Microscopy, combined with energy-dispersive X-ray spectroscopy (STEM-EDS) for a selected set of samples consisting of materials that incorporate Fe, Co, and Ni. Further, effects of N functionalities on stability of metal nanoparticles are investigated using a series of Pt-based catalysts. In this study, samples were analyzed using STEM and identical-location STEM to investigate differences in particle degradation mechanisms on N-doped supports with different N functionalities. This talk will examine findings related to effects of nitrogen on stability of Pt metal nanoparticles, and will also discuss and compare data analyses utilized in this work as they can be applied to other functional materials to improve understanding of their properties.