Thermal Conductivity Enhancement of Metal-organic Frameworks Employing Mixed Valence Metal Doping Technique

Abstract

Excellent adsorption properties of porous metal-organic frameworks (MOFs) render them highly potential adsorbent for adsorption heat pump applications. However, their thermal properties are not quite satisfactory. Aluminium fumarate is a bioavailable ligand-based metal-organic framework with promising water uptake capacity. In this study, aluminium fumarate was synthesized following a green synthesis route and was doped with Nickel and Cobalt material at 10% and 20% concentration to create a mixed-valence complex system. Their thermal diffusivity and thermal conductivity were studied at different compression (7 MPa, 17 MPa and 27 MPa) pressure over a temperature range of 30 °C to 110 °C. Metal doping enhances the thermal conductivity of the doped aluminium fumarate MOFs. Doping of cobalt has a greater effect compared to nickel and 20% cobalt doped aluminium fumarate shows the highest thermal conductivity at 7 MPa compression pressure.