High catalytic activity of MBenes-supported single atom catalysts for oxygen reduction and oxygen evolution reaction

Exploring earth-abundant and inexpensive electrocatalysts to realize efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is urgently desired for developing new clean and renewable energy storage and conversion technologies. In this work, through first-principles calculations, we have studied the ORR and OER catalytic activity of the single-atom catalysts (SACs) based on different two-dimensional (2D) MBenes substrates (marked as TM-M2B2O2, TM = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Pt, M = Ti, Mo and W). Significantly, Ni-Ti2B2O2, Cu-Ti2B2O2, Ni-Mo2B2O2, Ni-W2B2O2 and Pt-W2O2B2 exhibit promising ORR catalytic activity with low overpotential of 0.47 V, 0.57 V, 0.23 V, 0.43 V and 0.30 V, respectively, comparable to that of Pt (0.45 V). Meanwhile, Fe-Ti2B2O2, Co-Ti2B2O2, Fe-Mo2B2O2, Co-Mo2B2O2, Ni-Mo2B2O2, Fe-W2B2O2 and Co-W2B2O2 are promising OER catalysts with low overpotential of 0.51 V, 0.46 V, 0.48 V, 0.41 V, 0.54 V, 0.58 V and 0.30 V, respectively, comparable to that of RuO2 (0.42 V) and IrO2 (0.56 V). More importantly, ICOHP was used as a descriptor of ORR and OER catalytic activity in our work and shows good guidance for the further design of ORR, OER catalysts with high catalytic activity.