Low density and low thermal conductivity are common drawbacks of powder metal organic frameworks (MOFs)

which is one of key point limited the application of MOFs. MIL-101(Cr) as a typical water adsorption MOFs with high adsorption capacity is the major study object in this work. Two methods of directly dry-mixing and soaking are utilized to composite expanded graphite (EG) with MOFs

after compression by mold

a series of composite sorbents pellets with different EG content and packed density are developed. The optical microscope is utilized to observe the structure of materials

by which the influences of packed density and EG content on microscale structure are analyzed. The tests of saturated sorption capacity of pure MOFs and composites are carried out in a constant temperature and humidity chamber

whose results indicates the sorption capacity of pure MOFs will apparently reduce if the compression pressure is higher than 3 MPa. Accordingly

composite sorbents are prepared under relatively low compression pressure

whose sorption capacities are decrease with the increase of EG content

which is only caused by the decrease of MOFs content while there is no negative effects of EG on MOFs adsorption. Volume method is applied in adsorption kinetics study

which reveals the adsorption rates of pellets pure MOFs are much lower than powder pure MOFs. However

the composites shows 2.7 times higher surface diffusive coefficient than pellet pure MOFs ascribed of the appearance of more mass transfer channels caused by compression with EG. The results of thermal conductivity measurements of composite sorbent illustrate that thermal conductivities are obviously enhanced with the increase of EG content while a much smaller enhancement is observed by increasing packed density. Comparing with pure MOFs

the developed composites by dry-mixing method with EG mass content of 50%

with packed density of 408 kg·m-3 shows extraordinary high thermal conductivity of 2.76 W·m-1·K-1

which is 22 times higher than pure MOFs.