Metal-organic gas adsorbents

The history of crystalline gas adsorbents is old and starts with the mineral zeolite. Nowadays, there are successful synthetic techniques for the production of zeolites and zeotypes with controlled diameter pores. Moreover, processes able to produce porosity in pure organic and metal-organic skeletons have been developed. Typical compounds suitable for the topics of this chapter are shown in Fig. 3.4.6. They possess inner accessible spaces for gaseous guests to generate a gas inclusion state... 

Zeolites and metal-organic frameworks are two fascinating classes of microporous adsorbents with potential applications in separation processes, catalysis, and gas storage [1-4]. In particular, these materials have received a lot of attention due to their potential ability to reduce greenhouse gas emissions through carbon-capture schemes [5, 6]. 

Dietzel PDC, lohnsen RE, FjeUvag H et al (2008) Adsorption properties and structure of CO2 adsorbed on open coordination sites of metal-organic framework Niaidhtp) from gas adsorption, IR spectroscopy and X-ray diffraction. Chem Commun 41 5125-5127... 

Krishna R, Long JR (2011) Screening metal-organic frameworks by analysis of transient breakthrough of gas mixtures in a fixed bed adsorber. J Phys Chem C 115 12941-12950... 

Besides gas sorption and carbon capture, another important application of porous materials is the adsorption of volatile pollutants. Unlike other porous materials, such as zeolites or metal organic frameworks, PAFs are almost totally composed of hydrophobic aromatic frameworks and this makes them especially appropriate and effective for such a kind of application. As shown in Figure 8.4, ultra-high surface area PAF-1 is able to adsorb 1306 mg g (16.74 mmol g ) benzene and 1357 mg g (14.73 mmol g ) toluene at 298 K it should be noted that these values surpassed all porous materials at their time of publication. Even for PAF-5, whose surface area is 1503 m g , it can still adsorb 262.96cm (11.74mmol g ) benzene and 258.22cm g ... 

---