Designing of Highly Efficient Oxygen Evolution Reaction Electrocatalysts Utilizing A Correlation Factor: Theory and Experiment

Abstract

The theoretical prediction of the catalytic activity is very beneficial for the design of highly efficient catalysts. At present, most theoretical descriptors focus on estimating the catalytic activity and understanding the enhancement mechanism of catalysts, while it is also quite important to find a factor to correlate the descriptors with preparation methods. In this work, a correlation factor, the d electron density of transition metal ions, was developed to correlate the d band center values of transition metal ions with the preparation methods of amorphization and Al introduction. According to the results of theoretical simulations, the correlation factor not only exhibited favorable linear relationships with the theoretical overpotentials of (CoFeAl x ) 3 O 4 and (CoFeAl x ) 3 O 4 + (CoFeAl x )OOH systems but also correlated with two preparation methods by altering the volume of systems. Based on theoretical guidance, the electrocatalytic activities of the prepared (CoFeAl x ) 3 O 4 specimens were gradually improved by the preparation methods of amorphization and Al introduction, and the Am-CoFeAl-2-10h specimen exhibited a low kinetic barrier of 268 mV, fast charge transfer rate, and stable electrocatalytic activity. This strategy could be applied to design highly efficient catalysts by adjusting the correlation factor of the active site with suitable preparation methods.

Designing highly efficient oxygen evolution reaction electrocatalyst of high-entropy oxides FeCoNiZrOx: Theory and experiment

“…On the one hand, the approximate linear relationships between ε d and D d values indicated that, as shown in Figure 5 B, the local electronic structures of active site (ε d ) could be quantitatively adjusted by its coordination atomic plus electronic structures of D d . 13 , 48 On the other hand, the D d values were increased from HEO- O -1 to HEO-3 systems on account of the shortened Fe-O bond, which were consistent with the experimental XPS measurements. Hence, the pre-designed correlator D d could effectively correlate the modification method and chemical activity.…”

“…The pre-designed formula of D d and the occupied volume of d electrons ( V d ) was following 48 : where r Fe and r O denoted the ionic radius of Fe 3+ and O 2- ions. CN = 5 denoted the coordination number of surface Fe 3+ ions.…”