In Situ Electrochemical Route to Bromide Anion-Adsorbed Coral-like Porous Silver Microspheres Achieving Highly Selective Electroreduction of CO₂ to CO over a Wide Potential Range

Abstract

Silver catalysts play an irreplaceable role in the electroreduction of CO 2 to CO. Here, we report the structure of bromide anion-adsorbed coral-like porous microspheres of silver (Ag BACPSs). They are formed by in situ electrolysis of AgBr microparticles (AgBr MPs) at a very low potential of −0.8 V (vs reversible hydrogen electrode (RHE)). Each AgBr MP is completely transformed into a porous coral-like microsphere, and the mass activity is greatly improved. Simultaneously, every microsphere has an interconnected open-pore structure, and all surfaces of the material adsorb bromide anions. The increased active electron density on the surface of the material helps the CO 2 to obtain electrons on the surface of the electrocatalyst to form active species, which improves the selectivity of the catalytic material. Over a wide range of −0.4 to −0.9 V (vs RHE), the faradic efficiency for CO can be maintained above 91%, and the highest point can reach 98.7% at −0.6 V (vs RHE) in 0.5 M KHCO 3 solution. In addition, it has excellent stability. The obtained catalyst material has good large-scale application prospects.

Metal–Organic Framework-Derived BiIn Bimetallic Oxide Nanoparticles Embedded in Carbon Networks for Efficient Electrochemical Reduction of CO2 to Formate

“…Nevertheless, their inherent low current density and fast hydrogen evolution reaction are far from satisfactory . Constructing two-component or multicomponent catalysts to exert the synergistic effect of each component has been proven to be an effective method to enhance CO 2 RR or other catalytic reactions. ,− In particular, bimetallic catalysts can strengthen the selectivity and activity of CO 2 RR by stabilizing intermediates and inhibiting hydrogen evolution using synergistic effects. , The advantage of bimetals is that the binding energies of the reaction intermediates can be adjusted by tuning the electronic structure and atomic arrangement. , Compared to monometallic catalysts, bimetallic catalysts can reduce the energy barrier between the electrochemical reduction of CO 2 and the reaction intermediates . Therefore, the researchers have focused on the combination of other metals with Bi to obtain bimetallic bismuth-based electrocatalysts with high selectivity, stability, and low overpotentials, such as Bi–Sn, Bi–Cu, Bi–Ce, Bi–In, and so forth.…”

Construction of coral-like architectures of boron-containing compounds: coral-like boric acid and its application performances

“…1,2 Materials such as FeP@NC, CoMoO 4 , and Co 3 O 4 with coral-like frameworks have been reported to exhibit higher electrochemical performance in Na-ion and Li-ion batteries. [3][4][5][6] To date, a variety of approaches for constructing coral-like structures have been developed and reported, including solution reaction control and surface modifications, 1,7-9 chemical vapor depositions, 2 hydro/solvo-thermal approaches, 3,4,[10][11][12][13] electrolysis, 14 kinetic spray and electro-spinning techniques, [15][16][17] et al Despite these advances in fabricating coral-like architectures, the construction methodology towards realizing practical applications, with the feature of low cost and scalable production, remains challenging. In fact, natural stony coral skeletons are formed simply from the assembly of CaCO 3 directed by some polysaccharide molecules.…”