Abstract

The confinement of molecules within the van der Waals (vdW) gap between a two-dimensional material and a catalytic substrate can increase reaction rates, but the kinetic limits remain unclear. This work studies graphene etching in the vdW gap on platinum using in situ electron microscopy for O2, H2, and CO. The measured etching rates are mass-transport-limited over the investigated pressure and temperature range, and molecular dynamics simulations indicate multiple confinement-enabled etching pathways for CO. The study also extracts diffusion activation energies in the vdW gap and compares them with free-surface diffusion on platinum.

Abstract

The confinement of molecules within the van der Waals (vdW) gap between a two-dimensional material and a catalytic substrate can increase reaction rates, but the kinetic limits remain unclear. This work studies graphene etching in the vdW gap on platinum using in situ electron microscopy for O2, H2, and CO. The measured etching rates are mass-transport-limited over the investigated pressure and temperature range, and molecular dynamics simulations indicate multiple confinement-enabled etching pathways for CO. The study also extracts diffusion activation energies in the vdW gap and compares them with free-surface diffusion on platinum.

Abstract

The confinement of molecules within the van der Waals (vdW) gap between a two-dimensional material and a catalytic substrate can increase reaction rates, but the kinetic limits remain unclear. This work studies graphene etching in the vdW gap on platinum using in situ electron microscopy for O2, H2, and CO. The measured etching rates are mass-transport-limited over the investigated pressure and temperature range, and molecular dynamics simulations indicate multiple confinement-enabled etching pathways for CO. The study also extracts diffusion activation energies in the vdW gap and compares them with free-surface diffusion on platinum.

Abstract

The confinement of molecules within the van der Waals (vdW) gap between a two-dimensional material and a catalytic substrate can increase reaction rates, but the kinetic limits remain unclear. This work studies graphene etching in the vdW gap on platinum using in situ electron microscopy for O2, H2, and CO. The measured etching rates are mass-transport-limited over the investigated pressure and temperature range, and molecular dynamics simulations indicate multiple confinement-enabled etching pathways for CO. The study also extracts diffusion activation energies in the vdW gap and compares them with free-surface diffusion on platinum.