Energy conversion, classification

Oxidoreductases play a central role in the metabolism and energy conversion of living cells. About 25% of the presently known enzymes are oxido reductases [104]. The classification of oxidoreductases is presented in Fig. 3.38. The groups of oxidases, monooxygenases and peroxidases - dealing with oxidations - will be described in Chapter 4. 

Systematic Classification of Energy Conversions by Consilient Protein-based Machines... 

Process Intensification for Sustainable Energy Conversion Table 11.2 Classification of gas cleaning processes... 

A general overview of the different (conventional and alternative) systems with a presentation of the total energy conversion process and the resulting classification... 

Transition metal catalysts, specifically those composed of iron nanoparticles, are widely employed in industrial chemical production and pollution abatement applications [67], Iron also plays a cracial role in many important biological processes. Iron oxides are economical alternatives to more costly catalysts and show activity for the oxidation of methane [68], conversion of carbon monoxide to carbon dioxide [58], and the transformation of various hydrocarbons [69,70]. In addition, iron oxides have good catalytic lifetimes and are resistant to high concentrations of moisture and CO which often poison other catalysts [71]. Li et al. have observed that nanosized iron oxides are highly active for CO oxidation at low tanperatures [58]. Iron is unique and more active than other catalyst and support materials because it is easily reduced and provides a large number of potential active sites because of its highly disordered and defect rich structure [72, 73]. Previous gas-phase smdies of cationic iron clusters have included determination of the thermochemistry and bond energies of iron cluster oxides and iron carbonyl complexes by Armentrout and co-workers [74, 75], and a classification of the dissociation patterns of small iron oxide cluster cations by Schwarz et al. [76]. 

The second classification has been recently used in a later review article by Meijer and co-workers. This classification is mainly concerned with the mechanism of supramoiecuiar polymerization, which has been defined as the evolution of Gibbs free energy as a function of monomer conversion to polymer (p) from zero to one (p = 0 1) as the concentration, temperature, or some other environmental parameter is altered. This classification has been extremely effective in describing the vast array of examples of SPs, correlating mechanistic similarities with their covalent counterparts, which are widely understood to be classified mechanistically. In this scheme, the authors clearly identify the most fundamental difference between covalent and SPs as the difference in kinetic versus thermodynamic control. The authors argue that it is from this dramatic difference between covalent polymers and SPs, due to the reversibility of the noncovalent interactions, that SPs derive their special properties. This review did not include, however, SPs made from large macromolecular building blocks. 

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