Antiperovskite Nitrides CuNCo_3–xV_x: Highly Efficient and Durable Electrocatalysts for the Oxygen-Evolution Reaction

Abstract

Perovskite oxides have attracted much attention for enabling the oxygen-evolution reaction (OER) over the past decades. Nevertheless, their poor conductivity is still a barrier hindering their use. Herein, we report a catalyst prototype of Co-based antiperovskite nitrides CuNCo3–x V x (0 ≤ x ≤ 1) to be a highly effective OER electrocatalyst. The synthesized CuNCo3–x V x exhibits greatly enhanced activity and stability toward the OER in alkaline medium. The CuNCo2.4V0.6 shows a mere 235 mV of overpotential to reach 10 mA cm–2, which is comparable to that of Ir/C (232 mV). More importantly, the CuNCo2.4V0.6 is more durable than the conventional Ir/C catalyst. The CuNCo2.4V0.6 catalyst enabled a Zn–air battery to exhibit a cycle life of 143 h with a much higher cell efficiency. The V-substituted CuNCo2.4V0.6 provides a higher content of the desirable Co3+ species in the post-OER catalyst, which ensures a high activity over a long-term operation. With these enhanced effects enabled by the compositional flexibility of CuNCo3–x V x antiperovskite nitride, a feasible strategy for optimizing an electrocatalyst with tunable properties is provided.

Strategies for Engineering High‐Performance PGM‐Free Catalysts toward Oxygen Reduction and Evolution Reactions

“…The carbon materials are prone to be oxidized under high potentials so that the highly conductive noncarbon materials are emerging as promising candidates, for example, the metal nitrides. [ 96 ] Recently, our group developed a trimetallic nitride (Fe 2 Ni 2 N/Co) coupled with N‐doped carbon nanotubes (NCNT) as efficient OER/ORR catalysts. [ 80 ] The Fe 2 Ni 2 N/Co@NCNT catalyst was derived from spherical core–shell CoFe 2 O 4 /NiFe 2 O 4 spinel nanoparticles supported by CNT (denoted as CNFO@CNT) via facile ammonia pyrolysis.…”

Composition‐Tunable Antiperovskite CuxIn1−xNNi3 as Superior Electrocatalysts for the Hydrogen Evolution Reaction

“…Recently, a group of antiperovskite nitrides, ANM 3 , where A and M are both transition metals, have been widely investigated as the superconductor, which ensures a promising electrical conductivity for electrocatalysis. Given this, some novel antiperovskite nitrides have been employed as the efficient electrocatalysts, such as FeNNi 3 , CuNNi 3 , and CuNCo 3 . Previous studies and our recent work on CuNCo 3− x V x have indicated that the antiperovskite nitrides exhibited the compositional flexibility, which enabled the partial substitution of A‐site or M‐site metal by other transition metal .…”

“…[18] Previous studies and our recent work on CuN-Co 3Àx V x have indicated that the antiperovskite nitrides exhibited the compositional flexibility, which enabled the partial substitution of A-site or M-site metal by other transition metal. [18,19] By this substitution, the non-native metal atom occupied the position of original metal atom, and thus the derived antiperovskite nitride still preserved the pristine crystal structure. Such compositional flexibility offers a tailoring of the electronic structure of the involved transition metal cations by varying the composition and altering the coordination environment.…”

“…The Cu x In 1Àx NNi 3 (0 x 1) antiperovskite nitrides were prepared by a modified approach from our previous work. [18] In a typical synthesis protocol of the Cu x In 1Àx NNi 3 , the involved metal cations were coprecipitated with a specific ratio (see the experimental section in the Supporting Information). Then the collected powders underwent a heat treatment in an NH 3 flow gas to obtain the final antiperovskite nitrides.…”

“…Similar peak shifting caused by tuning the antiperovskite composition can be found in other reported works. [18,19] TEM images in Figure S2 a-c show that the synthesized InNNi 3 , CuNNi 3 and Cu 0.4 In 0.6 NNi 3 exhibit porous and sintered structure formed by the particle stacking of the antiperovskite nitrides. It is also observed that the particle size of Cu 0.4 In 0.6 NNi 3 is smaller than those of InNNi 3 and CuNNi 3 .…”