Surface Acidity as Descriptor of Catalytic Activity for Oxygen Evolution Reaction in Li-O₂ Battery

Abstract

Unraveling the descriptor of catalytic activity, which is related to physical properties of catalysts, is a major objective of catalysis research. In the present study, the first-principles calculations based on interfacial model were performed to study the oxygen evolution reaction mechanism of Li2O2 supported on active surfaces of transition-metal compounds (TMC: oxides, carbides, and nitrides). Our studies indicate that the O2 evolution and Li(+) desorption energies show linear and volcano relationships with surface acidity of catalysts, respectively. Therefore, the charging voltage and desorption energies of Li(+) and O2 over TMC could correlate with their corresponding surface acidity. It is found that certain materials with an appropriate surface acidity can achieve the high catalytic activity in reducing charging voltage and activation barrier of rate-determinant step. According to this correlation, CoO should have as active catalysis as Co3O4 in reducing charging overpotential, which is further confirmed by our comparative experimental studies. Co3O4, Mo2C, TiC, and TiN are predicted to have a relatively high catalytic activity, which is consistent with the previous experiments. The present study enables the rational design of catalysts with greater activity for charging reactions of Li-O2 battery.

Adsorption-energy-based activity descriptors for electrocatalysts in energy storage applications

“…Furthermore, as shown in Fig. 6, based on a three-phase interfacial model of 'Li 2 O 2 /catalysts/O 2 ', they found that the O 2 evolution and Li + desorption energies show linear and volcano relationships with the surface acidity of catalysts, respectively, resulting in a volcano relationship between the charging voltage and surface acidity [77]. Moreover, T.S.…”

“…They found that Liadsorbed sites on B-doped graphene, as the electronwithdrawing center, enhance charge transfer from Li 2 O 2 to the cathode and thus reduce the O 2 evolution barrier. Furthermore, they took surface acidity (defined as the energy change of catalysts with charge transfer) as a descriptor of charge transfer to study the electrocatalytic activity in the charging process [77,80,81]. They elucidated that the O-rich Co 3 O 4 (111) surface with a relatively low surface energy, promoting charge transfer from the Li 2 O 2 particles to the underlying surface, has a high catalytic activity to reduce overpotential and the O 2 evolution barrier [80].…”

Recent Progress in Electrocatalyst for Li‐O2 Batteries

“…[176] In his research, the surface acidity of transition-metal compounds (TMC: oxides, carbides, and nitrides) is strongly correlated with the corresponding charging voltage and desorption energies of Li + and O 2 over TMC (Figure 11d-f). According to this correlation, CoO is predicted to be as active as Co 3 O 4 in reducing charging overpotential, confirmed by their comparative experimental studies.…”

“…Reproduced with permission. [176] Copyright 2015, American Chemical Society. g) Digital photograph of gram-scale MnMoO 4 nanowires after co-precipitation for 60 min (P60-MMO) and schematic illustration of the ORR/ OER.…”

Strategies Toward Stable Nonaqueous Alkali Metal–O2 Batteries

“…Since the birth of Li-O 2 battery, a large number of materials have been investigated as potential OER catalysts, including noble/transition metals and their oxides, carbides, nitrides, and phosphides. [20] Based on the first-principles calculations, they found that the surface acidity of catalysts is the key parameter in determining desorption energies of Li + and O 2 , and charging voltage. [9e,13a,18] Taking some representative works as example, Nazar's group studied the role of Co 3 O 4 /reduced graphene oxide (rGO) composite as a catalyst for the Li-O 2 battery in 2012.…”