Charge effects on quinoline hydrodenitrogenation catalyzed by Ni-Mo-S active sites-A theoretical study by DFT calculation

The charge distribution on Ni-Mo-S active sites can affect hydrodenitrogenation (HDN) activity. In this study, a series of model Ni-Mo-S were developed with various charge distributions. For comparison, the charge distribution effects on quinoline HDN were studied. The results show that a lack of electrons and extra protons can both lower the orbital eigenvalue of the Ni-Mo-S, leading to stronger adsorption of nitrogen-containing compounds and inhibition of ammonia desorption. Electron deficiency will improve the generation of active hydrogen on the active sites but inhibit hydrogen transfer to the nitrogen compounds; extra protons can provide H+ to the nitrogen compounds, which will flexibly transfer between the nitrogen compound and active sites, thus improving the cleavage of the C-N bond. (C) 2021 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.

Automated summary

The charge distribution on Ni-Mo-S active sites plays a crucial role in hydrodenitrogenation (HDN) activity. Both electron deficiency and extra protons can modify the properties of the active sites, affecting the adsorption and desorption of nitrogen-containing compounds.