Heinke, L. / Wöll, C. (2013): „Adsorption and Diffusion in Thin Films of Nanoporous MOFs: Ferrocene in SURMOF Cu2(ndc)2(dabco)“. In: PhysChemChemPhys 15 (2013), 9295–9299
Adsorption and Diffusion in Thin Films of Nanoporous MOFs: Ferrocene in SURMOF Cu2(ndc)2(dabco)
Heinke, L. / Wöll, C. (2013)
PhysChemChemPhys 15 (2013), 9295–9299
The adsorption and diffusion of ferrocene (FC) in thin MOF films of type Cu2(ndc)2(dabco) were studied by X-ray diffraction and using a quartz-crystal microbalance (QCM) at different temperatures. A quantitative analysis of the uptake curves in the QCM during loading with FC from the gas phase yields 0.19 FC compounds per pore at a temperature of 305 K and of 0.06 at 335 K, respectively.
From an analysis of this temperature dependence we obtain an adsorption enthalpy of -30 kJ mol-1. A quantitative analysis of the time dependence of the QCM uptake curves yields very small diffusivities on the order of 10-19 to 10-17 m2 s-1, while the activation energy for diffusion amounts to +90 kJ mol-1. These results show that using a quartz crystal microbalance for uptake studies in SURMOFs is a valuable tool for investigating very slowly diffusing compounds in nanoporous materials.