Outlook adsorption

In the following sections, we shall begin our presentation with a discussion of the computational method, method developments and details of the calculations. Sections 3 and 4 are devoted to adsorption complexes of small probe molecules on ionic metal oxide MgO and a-AlaOa surfaces as well as in zeolites, respectively. Deposited transition metal particles on metal oxide surfaces and in zeolite cavities and complexes with them are addressed in Sections 5 and 6. Complexes of molecules adsorbed on nanoclusters of transition metals are considered in Section 7. The chapter will close with a summary and our outlook. 

As an outlook to further improvements of catalyst kinetics and durability in low-and high-temperature polymer electrolyte fuel cells, several possibilities are currently under investigation [73] (1) extended large-scale Pt and Pt-alloy surfaces [70] (2) extended nanostructured Pt and Pt-aUoy films [74] (3) de-alloyed Pt-alloy nanoparticles [75] (4) precious metal free catalyst as described by Lefevre et al. [76], e.g., Fe/N/C catalysts and (5) additives to the electrolyte which modify both adsorption properties of anions and spectator species and also the solubility of oxygen [77]. The latter approach is specific to fuel cells using phosphoric acid as electrolyte. 

This paper presents experimental results for the equilibrium adsorption of the shorter unbranched hydrocarbons, ethane, ethene, propane, and propene and of the linear and branched C4 alkanes n-butane and isobutane on Kureha activated carbon, a purely microporous material. The aim of the present study is to investigate comparative packing efficiencies of these light alkanes and alkenes and of the linear and branched C4 alkanes inside the adsorbent pores. An interpretation of the difference in the adsorption behaviour for these six adsorptives is given. In addition, thermodynamic properties like isosteric heat associated with adsorption are presented to characterize interactions between adsorptive and adsorbent and an outlook on mixture adsorption is discussed for this carbon. 

In this chapter, the key findings of such studies are briefly summarized and an outlook of promising trends in the treated fields is provided. In Seetion II, an introduetion to the theory of adsorption on soUds and a summary of basic models of heterogeneous surfaees will be given. The next sections are devoted to diflerent theoretical methods used in this field. 

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