Nanoporous NiSb to Enhance Nitrogen Electroreduction via Tailoring Competitive Adsorption Sites

Abstract

Ambient nitrogen reduction reaction (NRR) is attracting extensive interest but still suffers from sluggish kinetics owing to competitive rapid hydrogen evolution and difficult nitrogen activation. Herein, nanoporous NiSb alloy is reported as an efficient electrocatalyst for N2 fixation, achieving a high ammonia yield rate of 56.9 µg h−1 mg−1 with a Faradaic efficiency of 48.0%. Density functional theory calculations reveal that in NiSb alloy, Ni favors N2 hydrogenation while the neighboring Sb separates active sites for proton and N2 adsorption, which optimizes the adsorption/desorption of intermediates and enables an energetically favorable NRR pathway. This work indicates promising electrocatalytic application of the alloys of 3d and p block metals toward the NRR and provides an intriguing strategy to enhance the reduction of inert molecules by restraining the competitive hydrogen adsorption.

Mechanism driven design of trimer Ni1Sb2 site delivering superior hydrogenation selectivity to ethylene

“…Meanwhile, the deconvoluted Sb 4d XPS spectra exhibit four peaks corresponding to Sb 0 and Sb 3+ species (Fig. 4i ), which shift to lower binding energy compared to those of the monometallic Sb 27 . The positive shift of Ni 2p XPS peaks and simultaneously negative shift of Sb 4d XPS peaks indicate electron transfer from Ni to Sb, in line with the higher electronegativity of the guest Sb (2.05) than that of the host Ni (1.91).…”

Recent advances in nanostructured heterogeneous catalysts for N-cycle electrocatalysis

“…−1 NH3 yield would be quite reasonable for the electrosynthesis of NH3 to be competitive with the H-B process. In fact, even the most advanced NRR catalysts (catalytic systems) such as Bi nanocrystals (with K + in the electrolyte) [153], proton-filtering covalent organic frameworks [154], nanoporous NiSb [155], and nanoporous Pd3Bi [156] are still a long way from meeting the requirement for j of 0.25-0.5 A•cm −2 . Furthermore, for practical applications, such j must be maintained over long periods of operation (for example, a few months), and catalysts are difficult to avoid deactivation of active sites or decomposition.…”

Interface coupling induced built-in electric fields boost electrochemical nitrate reduction to ammonia over CuO@MnO2 core–shell hierarchical nanoarrays

“…[10][11][12][13][14][15][16] Nowadays, ammonia is mainly produced by the energy-intensive and highly polluting Haber-Bosch process. [17][18][19][20] Alternatively, electrocatalytic nitrate reduction to ammonia, due to its high efficiency and environmental characteristics, raises a storm of discussions and has a great impact on media and public imaginations. [21][22][23][24] The past decade has witnessed signicant progress in the study of electrocatalytic nitrate reduction to ammonia.…”