# Platinum Atoms Dynamics on the Surface of Hexagonal Boron Nitride Containing Vacancy Defects

## TL;DR

This paper explores how to control the formation of single-atom platinum catalysts on boron nitride surfaces with defects, using computational models and defect engineering.

## Contribution

The study introduces a defect-engineering approach to fabricate single-atom catalysts by extending the Volmer–Weber growth mechanism to include surface vacancy defects.

## Key findings

- Diffusion barriers on pristine surfaces do not reflect realistic growth conditions for single-atom catalysts.
- Surface vacancy defects significantly influence the atom-to-nanocluster ratio during catalyst fabrication.
- Ambient oxygen affects platinum interactions with defects and promotes clustering.

## Abstract

Single-atom catalysts
(SACs) have transformed the field of heterogeneous
catalysis by enabling efficient utilization of metal atoms and enhancing
the selectivity and activity of chemical reactions. The propensity
of metal atoms to aggregate into nanoclusters complicates the consistent
production of SACs and creates challenges in understanding their interactions
with naturally defected supports. Based on the example of platinum
SACs on hexagonal boron nitride, this study combines ab initio computational
methods with kinetic nucleation model to propose a route to controlled
fabrication of SACs through defect engineering. It shows that diffusion
barriers obtained for an isolated SAC on pristine surface do not represent
realistic growth conditions and highlights the importance of accounting
for collective atomic behavior when modeling nucleation and growth
processes. The study extends the classical Volmer–Weber mechanism
of nanocluster growth to account also for the presence of surface
vacancy defects and predicts the values of the single atom-to-nanocluster
ratio as a function of the surface defect density and platinum loading.
The effect of ambient oxygen on platinum SACs formation has been examined
to investigate its role in hindering metal interactions with defects
and promoting clustering.