Recent Advances in Studies on Organic Reactions in Water at High Temperatures and High Pressures

Chemical reactions in super- and subcritical water have been studied in our group over the decades, and recent advances are reviewed. The reaction mechanism in hydrothermal conditions is disclosed for ether and aldehyde in general form, and a new type of C-C bond formation is discovered in connection to the chemical evolution on primitive earth. Toward a new-generation hydrogen-fuel technology, it is proposed on the basis of physico-chemical reaction properties of formic acid that formic acid acts as a chemical tank for hydrogen storage and transportation. The hot-water chemistry is further discussed in the contexts of energy and environmental concerns, and its role in establishing green chemistry is stressed.