Antiperovskite nitride Cu3N nanosheets for efficient electrochemical oxidation of methanol to formate

Abstract

Perovskite oxides with flexible compositions and electronic structures have great potential for application in electrocatalytic water oxidation reactions. However, few studies have focused on the application of perovskite oxides in electrocatalytic oxidation reactions of organic molecules, probably due to the absence of active species because of the poor conductivity and high energy barrier of the surface reconstruction. Herein, we report Cu 3 N nanosheets with a typical antiperovskite structure as electrocatalysts for selectively converting methanol to formate. The as-prepared antiperovskite nitride Cu 3 N samples exhibit a Faradic efficiency exceeding 90% for methanol to formate over a wide potential range, which was further confirmed by online electrochemical mass spectrometry and in situ infrared reflectance absorption spectroscopy. Moreover, the high-resolution transmission electron microscopy, X-ray absorption spectroscopy, and in situ Raman spectroscopy results indicate that the core-shell structure formed by generating surface Cu(II) species triggers the electrocatalytic methanol oxidation reaction activity, whereas the pristine Cu 3 N core facilitates the electron transport inside the catalyst during the electrocatalytic process.This study provides a modelable scheme for the highly selective conversion of methanol and introduces a novel nonoxide perovskite material for the electrochemical conversion of small-organic molecules.

Tuning Electron Transfer in Atomic-Scale Pt-Supported Catalysts for the Alkaline Hydrogen Oxidation Reaction

“…42 Additionally, the N 1s and O 1s XPS spectra of the two prepared samples are also shown in Figure S3. 43 It also can be seen that the N 1s and O 1s XPS spectra no obvious changes after loading Pt in Pt/WN and Pt/ W 18 O 49 , respectively.…”

“…For the W 4f spectrum in Pt/WN (Figure S2a), the two peaks at 32.4 and 34.3 eV belong to the W–N bond, while 35.3 and 37.5 eV are classified as the W–O bond due to the inevitable surface oxidation by exposure to air. − W 4f in Pt/W 18 O 49 (Figure S2b) has only two peaks of the W–O bond at 35.8 and 38 eV, which are ascribed to W 4f 7/2 and W 4f 5/2 , respectively . Additionally, the N 1s and O 1s XPS spectra of the two prepared samples are also shown in Figure S3 . It also can be seen that the N 1s and O 1s XPS spectra no obvious changes after loading Pt in Pt/WN and Pt/W 18 O 49 , respectively.…”

Nano-Cu Derived from a Copper Nitride Precatalyst for Reductive Coupling of Nitroaromatics to Azo Compounds

“…Transition-metal nitrides (TMNs), an important class of inorganic materials featuring the interstitial nitrogen atoms within the metal matrix and the noble metal-like electronic structures, have been proven to be efficient in electro-, photo-, and thermal catalyses and are drawing broad interest in the catalysis community. − For example, Xu et al found that selenium-doped Co 4 N is an efficient electrocatalyst for hydrogen evolution reactions due to its modulated surface electronic structures . Yang et al employed tungsten nitride as a metallic photocatalyst for overall water splitting under red-light irradiation, confirming the important role of the metallic properties in exhibiting photocatalytic activity .…”

Tailoring the catalytically active sites in Co-based catalysts for electrochemical methanol upgrading to produce formate

“…15 In addition, Xu's group revealed that the in situ -formed Cu 2+ species on the surface of Cu 3 N could act as active sites for methanol electro-oxidation, which is the key active phase for the formation of formate. 18 Notably, owing to the relatively low structural stability of the transition-metal-based catalysts, the operational stability for long-term EMU catalysis is still not satisfactory to date, and needs to be strengthened via preferential microstructural design. Previous work reported that the nitrogen-doped carbon (Co–N–C) derived from the pyrolysis of a Co-based zeolitic imidazolate framework (ZIF-67) could not only effectively protect the active phase against structural collapse and degradation of activity, but also promote the electrochemical pre-oxidation process to accelerate the generation of more active sites for electro-oxidation reactions, benefitting from the enhanced conductivity.…”

“…To date, a series of transition-metal-based catalyst compounds have been explored for EMU, and current studies indicate that high-valence transition metal ions could serve as catalytically active sites for methanol-to-formate conversion. 5,15,[17][18][19][20][21][22] Hence, enriching local high-valence species or promoting the in situ generation of such active sites via an electrochemical pre-oxidation process could effectively improve EMU behavior. For example, Peng and colleagues fabricated an Fe 2 O 3 /NiO heterojunction catalyst, which could lead to the stabilization of high-valence Ni 3+ ions as active sites for EMU and further realize enhanced catalytic activity via beneficial Ni-O-Fe interfaces.…”