Co-enhancement on heat conduction and specific surface area of copper benzene-1,3,5-tricarboxylate (Cu-BTC) MOF with addition of graphene oxide

The classical metal-organic framework (MOF) Cu-BTC exhibits low thermal conductivity, which causes extreme temperature distribution inhomogeneity and limits its application as a support for methanol and steam reforming (MSR) thermocatalysts. A series of GO+Cu-BTC composites were synthesized via a one-pot hydrothermal method by combining Cu-BTC with graphene oxide (GO). The effects of GO with different oxidation degrees and mass fractions on the thermal conductivity from room temperature to 200 °C and the specific surface area of the composites were analyzed comprehensively, as well as the influence mechanism of GO addition on the thermal conductivity. The results indicated that the GO-induced changes in crystals characteristics, the formation of thermal conduction pathways through GO coverage and the new spaces between GO and Cu-BTC collectively achieve the co-enhancement on thermal conductivity and specific surface area and of the composites. For the composite with the same GO mass fraction, the thermal conductivity decreased with the increasing oxidation degree of GO and for the composite with the same GO oxidation degree, the thermal conductivity firstly decreased and then increased with the increasing mass fraction of GO. The specific surface area decreases with the increasing oxidation degree of GO and the optimum oxidation degree was 0.3. GO shows a significant enhancement in specific surface area at low mass fraction but caused a sharp decrease in specific surface area with the excessive GO mass fraction. Among all the composites, the optimal 0.1 wt.%GO-0.3+Cu-BTC exhibited the highest BET and Langmuir specific surface areas of 1394.55 m 2 /g and 1939.67 m 2 /g, which were 44 % and 43 % higher than those of pure Cu-BTC and its thermal conductivity at 25 °C, 100 °C and 200 °C achieved 0.31 W/(m· °C), 0.27 W/(m· °C) and 0.31 W/(m· °C), which were 211 %, 200 % and 53 % higher than that of pure Cu-BTC, respectively. It providing novel design strategies and experimental supports for the optimization of the heat transfer performance of MOFs developed as carriers for thermal catalytic systems.