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Si doped graphene as a metal-free catalyst to convert CO2 to methanol and ethanol with high selectivity and activity.

Single transition metal atom doped graphene has been experimentally proved to be effective for catalysing electrochemical reactions. However, oxygen reduction reactions (ORR) exhibit poor catalytic performance due to the high binding energy between the active site and the adsorbed species. Here, we propose a feasible strategy to modulate the binding strength of the oxygenated species on the graphitic nanosheet by introducing metal substrate gating. DFT calculation results reveal the remarkable enhancement of ORR performance with the confinement of Ni (111) surface, and the overpotentials for six different transition metal (TM) atoms doped pentagon|octagon|pentagon (5|8|5) graphene (TM@5|8|5G) on the Ni(111) surface can be significantly reduced, particularly for the case of Co@5|8|5G (from 0.98 V to 0.33 V). This is mainly attributed to the electron coupling between the metal substrate and TM@5|8|5G.Moreover, the catalytic activity can be well modulated by adjusting d band centres of TM atoms, leading to an ideal energy level of d band centre for TM@5|8|5G on Ni substrate (-1.48 eV), at which ORR can achieve the highest performance.

Single atom alloys (SAAs) based on TM doped Ru(0001) were investigated for their nitrogen reduction activity using density functional modelling. V@Ru(0001) was found to exhibit a low negative limiting potential and the TOF of the V@Ru(0001) catalyst was shown to be high.