Dual Functionalized Interstitial N Atoms in Co₃Mo₃N Enabling CO₂ Activation

Abstract

The introduction of light elements into the interstitial sites of metals can significantly modify their surface structure and electronic properties and thus enhance the catalytic performance. However, it is still unclear how the interstitial light elements promote the catalytic activity. Herein, N atoms are incorporated into the bimetallic CoMo system to synthesize Co3Mo3N as an efficient catalyst for reverse water–gas shift (RWGS) reaction. Compared to CoMo, Co3Mo3N significantly promotes the catalytic performance, where the removal of O-containing intermediates is identified as the rate-determining step. The enhanced activity is attributed to the dual functions of interstitial N atoms in Co3Mo3N, which provide additional sites for supplying H atoms to facilitate the hydrogenation of O-containing intermediates and accept electrons from Mo to weaken the binding ability of Mo to O-containing intermediates. These dual functionalized interstitial N atoms promote the redox cycle during the RWGS process and thus improve the catalytic performance. Our work provides an understanding of the interstitial light element-promoted catalytic performance relationship.

Enhanced N2 Activation on a Composite Co3Mo3N Nitride and La0.6Sr0.4Co0.2Fe0.8O3 Perovskite Cathode for High-Temperature Electrochemical Ammonia Synthesis

“…For the sample that was treated at 600 °C in humid N 2 , the Co–Co and Co–Mo interactions became less distinguishable, forming a broader peak. The Co–Mo peak shifted to a lower frequency and merged with the Co–Co peak, attributed to a change in the coordination of Mo in the structure . The Mo K-edge (Figure c) XANES similarly showed an edge shift of ∼1.0 eV between the fresh and 600 °C treated samples and a shift of the Mo–Co bond length.…”

“…This behavior may be attributed to the oxidation of cobalt, but the change is not drastic and the edge shift is within the error range since the spectral resolution was 0.38 eV for this beamline. Plotting the Fourier transform of the XAFS data (Figure 2 16 The Mo K-edge (Figure 2c) XANES similarly showed an edge shift of ∼1.0 eV between the fresh and 600 °C treated samples and a shift of the Mo− Co bond length. This suggests a slight positive oxidation state shift for molybdenum atoms, caused by infiltration of oxygen ions.…”

Modulating Electronic Structure with Copper Doping to Promote the Electrocatalytic Performance of Cobalt Disulfide in Li–O2 Batteries

“…The integrated COHP (ICOHP) below the Fermi level was calculated for quantitative measurement of bond strength. [ 39–41 ] The more positive ICOHP value of CoO bond and negative ICOHP value of OO bond after Cu doping further demonstrates the weakened interaction between LiO 2 intermediate and catalyst surface. Therefore, the incorporation of Cu heteroatom in CoS 2 can regulate its electronic structure efficiently to weaken the adsorption strength toward reaction intermediates during Li–O 2 battery operation.…”

Insight into the Dynamic Evolution of Co3Mo3N Bimetallic Nitride Surface during Ammonia Synthesis

“…The Co 3 Mo 3 N catalyst was prepared by the nitridation of precursor CoMoO 4 . CoMoO 4 was synthesized by a hydrothermal method at 160 °C for 6 h. 2 mmol (NH 4 ) 6 Mo 7 O 24 ·4H 2 O (Sigma-Aldrich, 99.0%) and 14 mmol Co­(NO 3 ) 2 ·6H 2 O (Aladdin, 99.99%) were used as raw materials with the molar ratio of 1Mo/1Co.…”