Self-Supporting Bi–Sb Bimetallic Nanoleaf for Electrochemical Synthesis of Formate by Highly Selective CO₂ Reduction

Abstract

Electrocatalytic reduction of CO 2 into valuable fuels and chemical feedstocks in a sustainable and environmentally friendly manner is an ideal way to mitigate climate change and environmental problems. Here, we fabricated a series of selfsupporting Bi−Sb bimetallic nanoleaves on carbon paper (CP) by a facile electrodeposition method. The synergistic effect of Bi and Sb components and the change of the electronic structure lead to high formate selectivity and excellent stability in the electrochemical CO 2 reduction reaction (CO 2 RR). Specifically, the Bi− Sb/CP bimetallic electrode achieved a high Faradic efficiency (FE formate , 88.30%) at −0.9 V (vs RHE). The FE of formate remained above 80% in a broad potential range of −0.9 to −1.3 V (vs RHE), while FE CO was suppressed below 6%. Density functional theory calculations showed that Bi(012)−Sb reduced the adsorption energy of the *OCHO intermediate and promoted the mass transfer of charges. The optimally adsorbed *OCHO intermediate promoted formate production while inhibiting the CO product pathway, thereby enhancing the selectivity to formate synthesis. Moreover, the CO 2 RR performance was also investigated in a flow-cell system to evaluate its potential for industrial applications. The bimetallic Bi−Sb catalyst can maintain a steady current density of 160 mA/cm 2 at −1.2 V (vs RHE) for 25 h continuous electrolysis. Such excellent stability for formate generation in flow cells has rarely been reported in previous studies. This work offers new insights into the development of bimetallic self-supporting electrodes for CO 2 reduction.

High Throughput Preparation of Bi-Sb Alloy Films for the Electrocatalytic Reduction of CO2 to Formate

“…26 In addition, the FE formate of a novel self-supporting Bi-Sb/CP bimetallic electrocatalyst could achieve 88% at −0.9 V vs RHE. 52 Although the FE formate of Bi-Sb alloys in this work is still lower than that of the pure Bi catalyst, the high j formate of Bi 45 Sb 55 indicates that the Bi-Sb interactions promote the intrinsic activity of formate formation (Fig. 5c), and the lower Tafel slope value of the Bi 45 Sb 55 catalyst also hints faster kinetics (Fig.…”

Synthesis of Bimetallic Nanoparticles and Applications—An Updated Review

“…A study employed this method and synthesized Co-Ni bimetallic nanoparticles that were used to detect tetracycline [73]. Similarly, Bi-Sb and Au@Ag core shells were synthesized by [74] and [75] using the same electrochemical method and used for the reduction of CO 2 and detection of thiram in juice and milk, respectively.…”

Surface-Enhanced Raman Spectroscopy for Boosting Electrochemical CO2 Reduction on Amorphous-Surfaced Tin Oxide Supported by MXene

“…3 Among these, liquid products such as formate are commercially advantageous due to their lower toxicity, higher energy density, and facile storage and transportation. 4 Consequently, the refinement of electrocatalysts that can proficiently drive the reduction of CO 2 to formate with enhanced activity and selectivity is of significant pertinence.…”

“…A wide range of CO 2 RR products, including carbon monoxide (CO), methane (CH 4 ), formic acid, or formate (HCOOH/HCOO – ), can be harnessed through appropriately engineered catalysts . Among these, liquid products such as formate are commercially advantageous due to their lower toxicity, higher energy density, and facile storage and transportation . Consequently, the refinement of electrocatalysts that can proficiently drive the reduction of CO 2 to formate with enhanced activity and selectivity is of significant pertinence.…”