Seite - 73 - in Advanced Chemical Kinetics

waspolarizedat0.05Vvs.Reversiblehydrogenelectrode (RHE)andpotential scanwasset to 1.0 V at 1 mV s 1, and the current in μA at top axis. The FTIR were collected at distinct electrode polarizations on steps of 0.1V. The negative bands correspond to the formation of chemical speciesandpositivebandscorrespondtoconsumptionofadsorbedchemical species. The band at 2345 cm 1 refers to CO2 formation [45] and it is observed only above 0.6 V vs. ReversibleHydrogenElectrode (RHE). Thepeak at 1860 cm 1 corresponds toCOOHdeflec- tion [45] observed at 0.2 V, which suggests the fast formation of acetic acid on Pt, in acid solution and adifficulty to generateCO2,which indicates complete ethanol oxidation. Peaks at 2981 and 2900 cm 1 correspond to CH2 and CH3 stretching, resulting from ethanol consumption. The peaks at 1715, 1353 and 1290 cm 1 correspond to the formation of alde- hydesandcarboxylicacids, suchasacetaldehydeandaceticacid [32, 37]. Thus, the conversion of chemical energy into electrical energy depends on the potential and the kinetics of the reactions; the development of newmaterials for a better exploitation of fuel is, then, limited by the characteristics of the electrochemical reactions kinetics. 7.Conclusion To understand the kinetic rates and laws of the dynamic processes of the energy transfers that involve the interaction between compounds, through the electronic excited states and the characteristics of the excited states is crucial to determine the applications, specially in energy conversion. Also, photochemical processes can be greatly exploited to cause the modifications in thematerials that enable their ability of energy transfer. Regarding to this, the rate constants of the photochemical reactions determine the paths that yield products and they are strictly related to the electronic excited states involved in the photochemical processes. If rate constants, intermediate structures and theirmechanisms of formation and the energetic balance involved in each change, it is possible to achieve the desired reaction control through experimental conditions control. New materials, capable of distinct elec- tronic processes that can influence photophysical and photochemical processes, are of great interest, nowadays. They become more and more specific and selective, aiming higher efficiencies of energy conversion, as well as faster and sustainable ways to promote degra- dation of pollutants. Also, as energy conversion in fuel cells, depends on the kinetic rates of electron generation, the development ofmaterial for complete oxidation reaction of ethanol would disseminate its usage. This means that there are no limits to develop newmaterials withproperties suitable for the needs of themodern society and those that promote changes using the abundant initiator of sunlight to trigger the changes are the most prominent candidates. Acknowledgements The authors thank toCNPq (grant 407619/2013-5) and FAPEG (grant 2012210267000923) for financial support. New Materials to Solve Energy Issues through Photochemical and Photophysical Processes: The Kinetics Involved http://dx.doi.org/10.5772/intechopen.70467 73