Using atomic layer deposited tungsten to increase thermal conductivity of a packed bed

摘要

This study investigated the effective thermal conductivity (k_(eff)) of packed-beds that contained porous particles with nanoscale tungsten (W) films of different thicknesses formed by atomic layer deposition (ALD). A continuous film on the particles is vital towards increasing k_(eff) of the packed beds. For example, the k_(eff) of an alumina packed bed was increased by three times after an ～8-nm continuous W film with 20 cycles of W ALD, whereas k_(eff) was decreased on a polymer packed bed with discontinuous, evenly dispersed W-islands due to nanoparticle scattering of phonons. For catalysts, understanding the thermal properties of these packed beds is essential for developing thermally conductive supports as alternatives to structured supports.