Competitive Trapping of Single Atoms onto a Metal Carbide Surface

Abstract

Controlling atomic adjustment of single-atom catalysts (SACs) can directly change its local configuration, regulate the energy barrier of intermediates, and further optimize reaction pathways. Herein, we report an atom manipulating process to synthesize Ni atoms stabilized on vanadium carbide (Ni SA -VC) through a nanofiber-medium thermodynamically driven atomic migration strategy. Experimental and theoretical results systematically reveal the tunable migration pathway of Ni atom from Ni nanoparticles to neighboring N-doped carbon (NC) and finally to metal carbide that was obtained by regulating the competitive adsorption energies between VC and NC for capturing Ni atoms. For CO 2to-CO electroreduction, Ni SA −VC exhibits an industrial current density of −180 mA cm −2 at −1.0 V vs reversible hydrogen electrode and the highest Faradaic efficiency for CO production (FE CO ) of 96.8% at −0.4 V vs RHE in a flow cell. Significant electron transfers occurring in Ni SA −VC structures contribute to the activation of CO 2 , facilitate the reaction free energy, regulate *CO desorption as the rate-determining step, and promote the activity and selectivity. This study provides an understanding on how to design powerful SACs for electrocatalysis.

An Energy-Efficient Integrated System by Coupling Carbon Dioxide Reduction and Methanol Oxidation to Produce the Identical Value-Added Formic Acid

“…The above results provided further evidence that the ECR product was formed from bubble CO 2 rather than from electrolyte or carrier. 44,45 In addition, the onset of Sn-MOF/CP (−0.60 V vs RHE) was more positive than SnO 2 /CP (−0.76 V vs RHE), and the current density of ECR on Sn-MOF/CP was higher than that on SnO 2 /CP at the same potential, suggesting that the ECR performance of Sn-MOF/CP was better than SnO 2 /CP. Meanwhile, although the current densities of ECR on Sn-MOF/CP and SnO 2 /CP increased as the applied potential shifted negatively, the current density of ECR on Sn-MOF/CP almost increased linearly, which showed that ECR activity of Sn-MOF/CP enhanced with the negative increase of the applied potential.…”

Steering the electronic communication between Al/Ru bimetallic clusters in metal–organic framework composites for accelerating hydrogen evolution kinetics

“…21 MOFs are often used as precursors to obtain "final products" by various calcination treatments to optimize conductivity and electrocatalytic performance. [22][23][24] Such post-processing methods, however, often have the disadvantages of high input, high energy consumption and low yield. 25 Therefore, it is urgent to reasonably decorate the structure of original MOFs to overcome the development bottleneck of electrocatalysts.…”

Modulating the Active Sites of VS2 by Mn Doping for Highly Selective CO2 Electroreduction to Methanol in a Flow Cell

“…Various metal sulfides are extensively employed in CO 2 ER; the component sulfur element can promote water activation and dissociation to form adsorbed H species (H*) that can react with the CO 2 molecule. , Group VB vanadium compounds, such as vanadium oxide (VO 2 ) and vanadium carbide (VC), have been exploited as an effective component of the catalyst in CO 2 ER. Vanadium ions (V 4+ and V 5+ ) can be utilized as a dopant to tune the local charge distribution of the pristine catalyst for improving the selectivity of a desired product in CO 2 ER. , Therefore, we can expect that VS 2 , one of the group VB transition-metal dichalcogenides (TMDs) possessing high conductivity, has potential application in CO 2 ER.…”