The spin state transition is an important factor that dominates the catalytic process, but there is still a great challenge in revealing its mechanism, which is still lacking in the catalyst model system. Based on this,Professor Lan Yaqian and Professor Liu Jiang of South China Normal UniversityIn this paper, a Hofmann cage with a dynamic spin state transition at the metal center can be chemically controlled by iodine treatment, which can be used as a model system for the study of spin-related structure-catalytic relationships. With the photocatalytic synthesis of H2O2 as the basic catalytic reaction, when the spin state of Fe(II) in the cage is high spin (HS), the photosynthesis of H2O2 is an indispensable sacrificial agent, because only the photocatalytic oxygen reduction reaction (ORR) occursAt low spin (LS), the ORR and water oxidation reaction (WOR) can be carried out at the same time, and the photosynthetic rate of H2O2 can reach 66000 M g-1 H-1 under visible light irradiation.
VASP Interpretation
To understand how the dynamic spin state transition behavior of Fe(II) in the Hofmann cage controls the catalytic performance, the catalytic performance was as1-iDFT calculations are performed in HS and LS states. Theoretical calculations show that the space charge separation of the two spin states is very similar. In different spin states, the Bader charge values of PT(II) are similar, while in the LS state structure, the Bader charge values of Fe(II) are more negative, and the Bader charge values of PT(IV) are corrected. The results showed that there was significant Fe(II)-PT(IV) charge transfer in the LS cage.
In addition, the authors investigated the ORR and WOR processes for HS and LS structures, respectively. The results show that both molecular oxygen and water molecules are chemically absorbed at the PT(II) site through the formation of PT-O bonds. For molecular oxygen uptake, the pt-o bond length of the LS state structure is 236, the pt-o bond length of the HS state structure is 228, i.e., the PT-O bond length of the HS state structure is shorter. The length of the PT-O bond between water and PT(II) is 2 in the LS state structure08, 2. in the HS state structure06 , the two are comparable. Chemical absorption of O2 and H2O molecules is predisposed to occur on open PT(II), which facilitates the removal of ORR and WOR from adsorption sites to substrates through light-induced electron and hole transfer.
on-off switching of a photocatalytic overall reaction through dynamic spin-state transition in a hofmann clathrate system. j. am. chem. soc.,, doi: ht-tps: