Long-Range Regulation of Se Doping for Oxygen Reduction of Atomically Dispersed Sb Catalysts for Ultralow-Temperature Solid-State Zn–Air Batteries

Abstract

Regulating the p-orbital valence electrons of atomically dispersed main-group metals to improve the inherent electrocatalytic activity has attracted extensive concerns. Herein, we designed and synthesized an atomically dispersed Sb−SeNC catalyst containing SbN 2 C 2 and SeC 2 structures, which have been identified by X-ray absorption spectroscopy and density functional theory (DFT) calculations. Sb−SeNC exhibits a high activity for the oxygen reduction reaction (ORR), and a Sb− SeNC-based flexible solid-state zinc−air battery (ZAB) can work efficiently at −40 °C, with a peak power density of 54.1 mW cm −2 and a rate discharge operation of about 44 h. DFT calculations further confirm the long-range regulation mechanism of the SeC 2 moiety for the ORR of SbN 2 C 2 and obtain the volcano relationship of U onset vs the Se−N distance. When the Se−N distance is 7.4 Å, the adsorption ability of active site Sb can be regulated to an optimal state related to the RDS: *O → *OH, while the smaller Se−N distance in short-range would lead to the excessive attenuation of adsorption ability of active site and decrease of ORR activity, which therefore yields the long-range regulation effect of Se doping on the ORR activity of SbN 2 C 2 . This long-range regulation strategy may provide a promising approach to boost the catalytic activity of main-group metal catalysts to achieve its application in ultralow-temperature solid-state ZABs.

Novel 2D carbon material T-graphene supported 3d transition metal single atoms as efficient oxygen reduction catalysts

“…In the current research, to boost the catalytic performance of catalysts, the main focus is placed on changing the central metal, 24 adjusting the coordination number [28][29][30] and the coordination environment [31][32][33] of the active central metal, or building defects [34][35][36] and doping heteroatoms into the carbon-based support. [37][38][39][40][41] In fact, investigating the effects of different carbon supports on the SACs is also very significant for designing ORR catalysts.…”

Selenium-doped carbon materials: synthesis and applications for sustainable technologies

“…A solid-state flexible ZAB was assembled utilizing Sb/Se/N co-doped carbon as a cathodic catalyst for ORR, and its performance was evaluated at −40 °C. 51 An OCV of 1.33 V, peak power density of 54.1 mW cm −2 , and a rate discharge operation of 44 h were achieved. The parameters were much better than those obtained for 20% Pt/C-based, and Sb/N doped carbon-based cathodes.…”

“…By employing ZIF-8 as a starting template, an atomically dispersed Sb/Se/N tri-doped carbon was prepared. 51 First, N-doped carbon and SeO 2 were pyrolyzed at 1000 °C. Then, SbCl 3 was added to the Se/N co-doped carbon, and the Sb/Se/N ternary-doped carbon was obtained upon a second pyrolysis at 950 °C.…”

Vacancy-Enhanced Sb–N4 Sites for the Oxygen Reduction Reaction and Zn–Air Battery

“…23 Niu et al found that the SeC 2 moiety could promote the intrinsic activity of SbN 2 C 2 sites through a longrange regulation mechanism. 24 Although significant progress has been made, the mechanism of formation of Sb sites is unclear and the unsatisfactory intrinsic activity caused by the fully occupied d shells of Sb atoms still needs to be improved. 26 It has been reported that adjusting the electronic structure of central metals is an effective strategy for enhancing the ORR activities of the M−N−C SACs.…”

“…In addition, Gu et al emphasized the vital role of epoxy groups on the second shell in optimizing the electronic structure of Sb–N 4 sites . Niu et al found that the SeC 2 moiety could promote the intrinsic activity of SbN 2 C 2 sites through a long-range regulation mechanism . Although significant progress has been made, the mechanism of formation of Sb sites is unclear and the unsatisfactory intrinsic activity caused by the fully occupied d shells of Sb atoms still needs to be improved .…”