Solar-Chemical Energy Conversion Via Reversible Liquid Phase Diels-Alder Reactions. Final Technical Report

摘要

Thermochemical energy conversion at moderate or low temperature (< about 400 exp 0 C) employing liquid phase components throughout a cycle is suggested as a promising concept for high-efficiency conversion of solar energy to a convenient chemical form. In particular, we propose liquid phase Diels-Alder cycloaddition chemistry as an important class of reversible reactions for such low or moderate temperature thermochemical energy conversion systems. One of the important attributes of thermally driven Diels-Alder reactions is their concerted mechanism, with consequent high yields and efficiencies relative to liquid photochemical systems. Since the systems we propose involve organic species, with thermal stability concerns about 400 exp 0 C, it is important to demonstrate equilibrium shift capability for the highly energetic reactions sought. We have therefore carried out experimental studies with model liquid Diels-Alder systems that clearly demonstrate the degree of control over equilibrium available through substituent entropy effects. These results are of importance as regards subsequent systematic identification of Diels-Alder reactions having ideal thermochemical and physical properties. (ERA citation 09:013480)