e<sub>g</sub> occupancy as an effective descriptor for the catalytic activity of perovskite oxide-based peroxidase mimics.

Wang, Xiaoyu; Gao, Xuejiao J; Qin, Li; Wang, Changda; Song, Li; Zhou, Yong-Ning; Zhu, Guoyin; Cao, Wen et al. · Nat Commun · 2019

basic_science · Level V

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Abstract

A peroxidase catalyzes the oxidation of a substrate with a peroxide. The search for peroxidase-like and other enzyme-like nanomaterials (called nanozymes) mainly relies on trial-and-error strategies, due to the lack of predictive descriptors. To fill this gap, here we investigate the occupancy of e<sub>g</sub> orbitals as a possible descriptor for the peroxidase-like activity of transition metal oxide (including perovskite oxide) nanozymes. Both experimental measurements and density functional theory calculations reveal a volcano relationship between the e<sub>g</sub> occupancy and nanozymes' activity, with the highest peroxidase-like activities corresponding to e<sub>g</sub> occupancies of ~1.2. LaNiO<sub>3-δ</sub>, optimized based on the e<sub>g</sub> occupancy, exhibits an activity one to two orders of magnitude higher than that of other representative peroxidase-like nanozymes. This study shows that the e<sub>g</sub> occupancy is a predictive descriptor to guide the design of peroxidase-like nanozymes; in addition, it provides detailed insight into the catalytic mechanism of peroxidase-like nanozymes.

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