Physicochemical study on supercritical fluids and their industrial use

In this study, we confirm a tetrahedral structure for a Co2+ complex in sup ercritical water instead of the octahedral structure in normal water. The a bsorption spectra of Ru2+ complexes were observed for only stable species s uch as [Ru(phen)(3)](2+) in supercritical water. The photochemistry of uran yl(VI)-tributylphosphate(TBP) complex in supercritical carbon dioxide(scCO( 2)) was studied in the pressure range of 8-40 MPa and from 289 to 336K. In order to examine the hydrogen-bond structures and molecular motions of supe rcritical water and non-aqueous solvents, their H-1 spin-lattice relaxation times were measured under sub- and supercritical conditions by using high- pressure NMR. NiMo/Al2O3 was chosen as a catalyst because of its catalytic activity for hydrocracking aromatic structures. (C) 2000 Elsevier Science L td. All rights reserved.