Bond-Derived Orbitalwise Coordination Number as an Accurate Reactivity Descriptor for Oxygen Electrochemistry in Transition-Metal Oxides

TL;DR

This paper introduces a bond-derived orbitalwise coordination number as an effective and computationally efficient descriptor for predicting oxygen electrochemical activity in transition-metal oxides, aiding catalyst screening.

Contribution

It proposes a new electronic-structure-based descriptor that correlates strongly with catalytic activity and can be universally applied to various transition-metal oxides.

Findings

The descriptor accurately predicts activity in oxygen electrochemistry.

$eta$-MnO$_2$ with specific vacancy exhibits optimal activity.

The method aligns well with experimental results.

Abstract

Unraveling a descriptor that is correlated with catalytic reactivity is essential for fast screening for the optimal catalysts for a given catalytic reaction. Herein, we propose bond-derived orbitalwise coordination number ($\overline{CN}^\alpha$, $\alpha$= $s$ or $d$) as a simple and accurate descriptor used for transition metal (TM) oxides that takes into account both geometrical and electronic structures around active sites, and avoids excessive computation burden. This descriptor has a strong scaling relation with the activity in oxygen electrochemistry, enabling us to readily screen for the optimal catalyst for $\beta$-MnO$_2$. $\beta$-MnO$_2$ with $\overline{CN}^\alpha$=5.6 by creating an oxygen vacancy on (110) surface exhibits the best oxygen electrochemical activity, which is well consistent with experimetal result. This descriptor can be universally applied to other TM oxides, e.g. RuO$_2$, opening up a new route as a guideline to design novel catalysts in catalytic reactions.