Engineering 3d–2p–4f Gradient Orbital Coupling to Enhance Electrocatalytic Oxygen Reduction

Abstract

The development of highly efficient and economical materials for the oxygen reduction reaction (ORR) plays a key role in practical energy conversion technologies. However, the intrinsic scaling relations exert thermodynamic inhibition on realizing highly active ORR electrocatalysts. Herein, a novel and feasible gradient orbital coupling strategy for tuning the ORR performance through the construction of Co 3d‐O 2p‐Eu 4f unit sites on the Eu2O3–Co model is proposed. Through the gradient orbital coupling, the pristine ionic property between Eu and O atoms is assigned with increased covalency, which optimizes the eg occupancy of Co sites, and weakens the OO bond, thus ultimately breaking the scaling relation between *OOH and *OH at Co–O–Eu unit sites. The optimized model catalyst displays onset and half‐wave potential of 1.007 and 0.887 V versus reversible hydrogen electrode, respectively, which are higher than those of commercial Pt/C and most Co‐based catalysts ever reported. In addition, the catalyst is found to possess superior selectivity and durability. It also reveals better cell performance than commercial noble‐metal catalysts in Zn–air batteries in terms of high power/energy densities and long cycle life. This study provides a new perspective for electronic modulation strategy by the construction of gradient 3d–2p–4f orbital coupling.

Boosting Urea Electrooxidation Activity of Ni5P4 by Vanadium Doping for Urea-Assisted Renewable Energy Conversion Devices

“…1−7 Unfortunately, in practical applications, the actual potential to drive OER is as high as 1.8 V, even to 2.0 V, much higher than 1.23 V, the theoretical thermodynamics potential. 7,8 This high input potential inevitably causes extra energy consumption. Therefore, replacing OER with more easily oxidizable species is an effective and environmentally friendly way.…”

“…As a prominent half-reaction, the electrocatalytic oxygen evolution reaction (OER) has attracted great attention in the diverse energy-related realm, such as producing clean hydrogen from overall water splitting, fuel cells, renewable metal-air batteries, and CO 2 reduction. − Unfortunately, in practical applications, the actual potential to drive OER is as high as 1.8 V, even to 2.0 V, much higher than 1.23 V, the theoretical thermodynamics potential. , This high input potential inevitably causes extra energy consumption. Therefore, replacing OER with more easily oxidizable species is an effective and environmentally friendly way. , Among them, the urea oxidation reaction (UOR), which has a lower theoretical voltage of only 0.37 V cuts a striking figure. − Moreover, UOR holds great significance for the treatment of urea-rich industrial wastewater and domestic sewage. , Thus, UOR is an ideal alternative to the conventional OER.…”

Cross-Linked Double-Active Centers for Efficient pH-Universal Oxygen Reduction Catalysis

“…The N 1s spectrum shows symmetrical and sharp peaks of pyridine N, pyrrole, respectively N, graphitic N, and oxidized N (Figure I and Table S3). ,, Interestingly, the N 1s XPS peak of 399.4 eV can be attributed to the bonding of N atoms to metals. It is obvious from the figure that the percentage of pyridine-N in samples loaded with Fe and Mn elements decreases, which further proves the coordination of N with Fe and Mn ions.…”

Recent advances in nonmetallic modulation of palladium-based electrocatalysts

“…Exploring high-performance electrocatalysts to promote the sluggish reaction kinetics of electrocatalytic reactions is quite essential. In comparison to the non-noble metal catalysts, Pt-based noble metals are still the state-of-the-art and most extensively used catalysts in the field of electrocatalysis as a result of their attractive catalytic performance and corrosion resistance, but their large-scale commercialization is greatly impeded to the scarce reservation and fancy price [6][7][8][9] . Thus, seeking non-Pt-based noble metals as an effective alternative has become urgently needed [10] .…”