Adsorbing and Activating N₂ on Heterogeneous Au–Fe₃O₄ Nanoparticles for N₂ Fixation

Abstract

Electrochemical nitrogen reduction reaction (NRR) is a promising approach to convert earth‐adundant N2 into highly value‐added NH3. Herein, it is demonstrated that the heterogeneous Au–Fe3O4 nanoparticles (NPs) can be adopted as highly efficient catalysts for NRR. Due to the synergistic effect of the strong N2 fixation ability of Fe3O4 and the charge transfer capability of Au, the Au–Fe3O4 NPs show excellent performance with a high yield (NH3: 21.42 µg mgcat−1 h−1) and a favorable faradaic efficiency (NH3: 10.54%) at −0.2 V (vs reversible hydrogen electrode), both of which are much better than those of the Au NPs, Fe3O4 NPs, as well as core@shell Au@Fe3O4 NPs. It also exhibits good stability with largely maintained performance after six cycles. The N2 temperature‐programmed desorption, surface valance band spectra, and X‐ray photoelectron spectroscopy collectively confirm that Au–Fe3O4 NPs have a strong adsorption capacity for the reaction species and suitable surface structure for electronic transfer. The theoretical calculations reveal that Fe provides the active site to fix N2 into *N2H while introducing Au optimizes the adsorption of NRR intermediates, making the NRR pathway on Au–Fe3O4 along an energetic‐favorable process and enhancing the NRR.

Glycerine-based synthesis of a highly efficient Fe2O3 electrocatalyst for N2 fixation

“…[8][9][10] To date, a number of catalysts have been developed for the NRR, including noble metals, [11][12][13] transition metals, 14,15 metalfree materials, [16][17][18] metal-C composite materials [19][20][21] and Au-Fe 3 O 4 . 22 These catalysts have demonstrated potential applications in the NRR with improved FE and NH 3 yield. Most of the catalysts were synthesized with the assistance of surfactants (structure-directing agents) through solution methods.…”

A Novel Nonenzymatic Hydrogen Peroxide Sensor Based on Magnetic Core-Shell Fe3O4@C/Au Nanoparticle Nanocomposite

“…It is difficult to discriminate Fe 3 O 4 phases from γ -Fe 2 O 3 by only using XRD patterns due to the similarity of patterns, and XPS is conducted to characterize the electronic structures of Fe element in the nanocomposite, which is known to be sensitive to Fe 2+ and Fe 3+ cations. Figure 2 (c) presents two peaks at the binding energies of 724.4 and 711.4 eV, which correspond to the maximum intensity of Fe 2p1/2 and Fe 2p3/2, illustrating the coexistence of Fe 2+ and Fe 3+ cations in Fe 3 O 4 @C/AuNPs [ 23 ]. Peaks of Au are also shown in Figure 2(d) , corresponding to Au 4f2/7 and Au 4f2/5, respectively.…”

The Role of Defects in Metal–Organic Frameworks for Nitrogen Reduction Reaction: When Defects Switch to Features

“…[ 61,77 ] To date, various strategies have been implemented to achieve effective rich‐defect electrocatalysts by prompting defects of various types and altering their concentrations or position in host materials. [ 75,78–82 ]…”