二核钛氧簇Ti2O4+/-离子裂解水脱氢的机理研究OA

The reaction mechanisms of H2 generation by titanium oxide ions Ti2O4+/-reacting with H2O are stud-ied by DFT calculations.The results show that the ground-state structures of Ti2O4+and Ti2O4-are similar,both featuring two terminal oxygens symmetrically attached in a trans-manner to the two Ti atoms in the Ti2O2 four-membered ring plane.For the ground state structure of Ti2O4-,the unpaired electron is localized on one of the Ti atoms;whereas in Ti2O4+,the unpaired electron resides on a terminal oxygen,forming an elongated radical-containing(Ti-O·)bond.The reaction mechanisms of Ti2O4+/-in cleaving water for dehydrogenation were in-vestigated by calculating the reaction potential energy surfaces,considering various possible pathways for the acti-vation and dissociation of H2O molecules on Ti2O4+/-.The results indicate that the anionic and cationic Ti2O4+/-share similar process of H2 generation via splitting water:H2O molecules are firstly dissociated on Ti2O4+/-form-ing-OH groups;Ti-H and Ti-OOH groups are then formed by intra-molecular hydrogen transfer;H2 is pro-duced via the interaction of these two groups and finally desorbed.