Dimethylamine formation from N-nitrosodimethylamine adsorbed on the Ni{1 1 1} surface from first principles

• High H coverage coadsorbed decreases the activation energy for NDMA dissociation.
• Dimethylamine formation from NDMA and H coadsorbed on Ni{1 1 1} is favorable.
• H is needed for dimethylamine formation after NDMA dissociation.

N-nitrosodimethylamine (NDMA) reaction with coadsorbed hydrogen on the Ni{1 1 1} surface has been investigated in the low coverage regime using first-principles calculations. The results of previous calculations found that isolated NDMA adsorbs on the Ni surface in two different competitive ways as the two most stable configurations. In the upright configuration the adsorption is via the ON end. This configuration is slightly preferred energetically to the flat configuration, in which the interaction is via the ONN plane. However, this last configuration leads to a facile dissociation of the NDMA molecule via the NN bond. In the present article, it is found that the formation of dimethylamine (DMA) and NO on the surface is preferred to the formation of other products on the surface from the flat configuration in the low NDMA coverage regime. Hydrogen is needed for the DMA formation. Besides that, high coverage of adsorbed hydrogen decreases the activation energy needed to break the NN bond in the flat adsorption configuration.

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