Effective Thermal Conductivity of Packed Beds and Benefit of in-Situ W ALD: Original Sample Preparation Technique

In-situ W ALD deposits uniformly throughout a packed bed of porous particles and particle internal volume and display increased effective thermal conductivity (k_eff).  An original sample preparation technique was developed for measuring thermal conductivity of packed beds coated by ALD.  Intimate particle contact surfaces were revealed from 3D X-ray.  Imaging in-situ ALD particles confirm wetted surfaces between particles; these contact surfaces are theorized to increase k_eff of the packed bed.  The conformal self-limited ALD reaction maintains porous properties of the starting material, preserves surface area of the catalyst support, and improves k_eff.