(Invited) N-Doped Carbon-Based Materials: Improved Fundamental Understanding through Comprehensive Characterization

Abstract

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 therefore, they are intrinsically challenging to understand, requiring a wide range of characterization techniques.This talk will discuss a family of N-doped catalysts derived from a series of N-doped carbon nanospheres. N-doped nanospheres, produced solvothermally, are synthesized 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. Platinum and non-platinum metals were incorporated using various synthetic routes, targeting formation of either metal nanoparticles or atomically-dispersed species. Understanding the surface and bulk chemistry of these materials is essential for elucidating the effects of nitrogen dopants on nucleation and stability of metals across the periodic table. Trends observed experimentally will be compared with metal adsorption computations with the goal of extending beyond experimental data to make predictions for more efficient catalyst development. Within a catalyst layer, the surface chemistry also affects interactions with ionomer, and both the nature of the metal and its morphology, as well as the functionality of nitrogen impacts these interactions.