Modeling the precursor utilization in atomic layer deposition on nanostructured materials in fluidized bed reactors

• We model atomic layer deposition in fluidized beds on nanostructured materials.
• We assess the impact of the precursor transport on the precursor utilization.
• Fast ALD kinetics enable complete precursor uptake at high surface conversion.
• We study the effect of the nanoparticle agglomeration on the process dynamics.
• We propose the optimal reactor height depending on operating conditions.

We present a multiscale dynamic model as a means of understanding and optimizing the precursor utilization during atomic layer deposition (ALD) on nanoparticles and micron-sized nano-porous particles in fluidized bed reactors. We used as case study the deposition of alumina using trimethylaluminum and water on both, titania nanoparticles and micron-sized nano-porous γγ-alumina particles under low (∼1 mbar) and atmospheric pressure. In doing so, we assess the effect of the precursor transport, from the inlet of the reactor to the particles active surface, on the precursor utilization efficiency. Our results show that, at proper operating conditions, fast ALD reaction kinetics enables the saturation of the particles surface area with hardly any loss of precursors. Finally, simple scaling rules for the optimization of the precursor utilization are proposed.