Tuning Coordination Structures of Zn Sites Through Symmetry‐Breaking Accelerates Electrocatalysis

Abstract

Manipulating the coordination environment of individual active sites in a precise manner remains an important challenge in electrocatalytic reactions. Herein, inspired by theoretical predictions, we present a facile procedure to synthesize a series of symmetry‐breaking zinc metal‐organic framework (Zn‐MOF) catalysts with well‐defined structures. Benefiting from the optimized coordination microenvironment regulated by symmetry‐breaking, Zn‐N2S2‐MOF exhibits the best performance of N2 reduction reaction (NRR) with NH3 yield rate of 25.07 ± 1.57 µg h−1 cm−2 and Faradaic efficiency of 44.57 ± 2.79% compared with reported Zn‐based NRR catalysts. X‐ray absorption near‐edge structure shows that the symmetry‐breaking distorts the coordination environment and modulates the delocalized electrons around the Zn sites, which favors the formation of unpaired low‐valence Znδ+, thereby facilitating the adsorption/activation of N2. Theoretical calculations elucidate that low‐valence Znδ+ in Zn‐N2S2‐MOF can effectively lower the energy barrier of potential determining step, promoting the kinetics and boosting the NRR activity. This work highlights the relationship between the precise coordination environment of metal sites and the catalytic activity, which offers insightful guidance for rationally designing high‐efficiency electrocatalysts.This article is protected by copyright. All rights reserved

Role of Charge Accumulation in MoS2/Graphitic Carbon Nitride Nanostructures for Photocatalytic N2 Fixation

“…The high-resolution TEM (HRTEM) image of MIX reveals an interlayer distance of 0.61 nm indexed to the (002) plane of MoS 2 (Figure d), indicating that the number of MoS 2 layers in the MIX sample is about 3–5. The HRTEM image of MLCN is shown in Figure e, and a typical lattice fringe with a spacing of 0.27 nm assigned to the (100) planes of MoS 2 can be observed. , In addition, the (002) crystallographic planes of MoS 2 clearly state that monolayer MoS 2 is anchored on 2D GCN. The SAED in Figure c illustrates that the MoS 2 in MDCN is a mixed grain on the surface of GCN.…”

Biomimetic Design of a Dynamic M–O–V Pyramid Electron Bridge for Enhanced Nitrogen Electroreduction

“…To address the above-mentioned challenges, substantial efforts have been devoted to exploring various catalysts, such as noble metals (e.g., Ru, Pd, and Au), − transition metals (e.g., oxides, sulfides, nitrides, and carbides), − and nonmetals. − Among these candidate catalysts, Ru-based materials as a second-generation NH 3 catalyst have exhibited great promise for eNRR owing to the appropriate N 2 adsorption energy and considerably lower required potential than that of other nonmetals and metals. − Furthermore, the performance of catalysts has been promoted by engineering morphology and constructing electronic structures. − Recently, single-atom catalysts (SACs) have stimulated tremendous interest in electrocatalysis attributed to their maximal atomic utilization efficiency and unique electronic structure, potentially driving intrinsic high eNRR activity. ,, Although various strategies for atomic/electronic structure modulation have been explored (such as high entropy, , symmetry breaking, , amorphous support, , alloying, , and synergistic effect, , Figure S2), traditional SACs are restricted to unidirectional electronic structure regulation (Figure S3), leading to either a unidirectional delocalization or localization of electrons at active sites. As a result, the electronic structure that achieves optimal NH 3 activity is confined to a very narrow overpotential range (∼0.1 V, Figure a). , As the overpotential shifts further negative, the eNRR sites transition to HER sites due to unidirectional electron capture, leading to a sharp decline in the NH 3 yield rate and FE.…”

Antimony-Doped Wide Bandgap Molybdenum Trioxide with Enhanced Localized Surface Plasmon Resonance for Nitrogen Photofixation

“…Ammonia is a critical chemical supporting economic development and human health in the fields of agricultural fertilizers, industrial chemicals, and zero-carbon fuels. − Most commercial ammonia is produced by the Haber–Bosch process, for which the resultant high energy consumption and greenhouse gas emissions have yet to be addressed. − The artificial photosynthesis of ammonia has been recognized as one of the most sustainable ways to achieve sustainability using solar energy. However, converting nitrogen molecules to ammonia in pure water is challenging due to the thermodynamic and kinetic requirements.…”