Carbon materials serve as a porous, stable, and conductive high surface area platform for the deposition and dispersion of noble metal nanoparticles leading to a catalytically active surface. However, these systems still lack the long-term stability and durability necessary for practical implementations due to nanoparticle dissolution and agglomeration. Doping carbon supports with nitrogen has been shown to increase nanoparticle dispersion and stability compared to their undoped equivalent. Theoretical work has pursued uncovering the novel fundamental groundwork behind doping and further enhance the beneficial interactions. Much of the previous theoretical work probes only a single defect – metal combination leaving interstudy comparisons speculative, given an array of differing computational parameters. Systematic studies that provide insights into these underlying interactions are scarce. A variety of nitrogen functionalities available further complicates these studies. It is important to explore different representations that are modeling the catalyst–support interactions to further understand computational intricacies.   <br/>A systematic framework was designed to probe and exploit periodic trends in understanding these fundamental interactions and evaluating different computational modeling approaches to delineate the impact of doping. Twelve transition metals were explored, including known catalytic standards and promising non-precious alternatives, over truncated and periodic graphene models with graphitic nitrogen defects. It was discovered that computational treatment affected the magnitudes of adsorption energies between the metals and support. Between truncated and periodic boundary condition models, metals generally followed the same trends in their method of interaction with the carbon support. Overall, the addition of the dopant improved the metal – support interactions by promoting electronic rearrangement from the metals’ d- to s-orbitals for then greater orbital overlap with the graphene, shown with increased favorable adsorption. Furthermore, periodic trends were systematically observed and used to elucidate the nature of these relevant fundamental metal – support interactions.

Probing metal catalysts support interactions with graphitic nitrogen dopants to investigate periodic trends

ACS Spring Meeting 2021

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