Bismuth Oxides with Enhanced Bismuth–Oxygen Structure for Efficient Electrochemical Reduction of Carbon Dioxide to Formate

Abstract

Electrochemical conversion of carbon dioxide (CO 2 ) into high-value chemical products has become a dramatic research area because of the efficient exploitation of carbon resources and simultaneous reduction of atmospheric CO 2 concentration. Herein, we report the bismuth-based catalyst in the efficient electroconversion of CO 2 for the formation of formate with a maximum Faradaic efficiency of 91% and partial current density of ∼8 mA cm −2 at −0.9 V vs RHE. Experimental and theoretical results show that the bismuth−oxygen structure of bismuth oxides is beneficial for a higher adsorption of CO 2 and the ratedetermining route switching from the initial fast pre-equilibrium of electron transfer process to the subsequent hydrogenation step, accompanied by a lower free energy of intermediate. This work may offer valuable insights into crystal structure engineering to achieve efficient electrocatalysts for selective CO 2 reduction toward generation of valuable products.

Boosting thermo-photocatalytic CO2 conversion activity by using photosynthesis-inspired electron-proton-transfer mediators

“…For the Bi-H x covered by ~3 nm amorphous Bi 2 O 3 layer, tunneling of the hot carrier to the out surface is still feasible due to the high energy of the hot charge carriers generated by LSPR and a high-density of defect states in the amorphous layer. A similar result has been observed on Bi catalysts for electrochemical H 2 production and CO 2 reduction in previous reports 22 , 24 . In addition, the specific surface areas of the two samples were studied by the Brunauer–Emmett–Teller (BET) method based on the nitrogen adsorption isotherm, showing that the BET surface areas of Bi-H x and Bi are 3.3356 and 2.1039 m 2 g −1 , respectively.…”

“…1 ). The two samples exhibit similar O 1 s XPS spectra that can be deconvoluted into three peaks corresponding to, Bi-O bands (529.3 eV), surface hydroxyl oxygen (530.8 eV), and adsorbed O 2 (532.7 eV), further confirming the generation of Bi-O in Bi 2 O 3 on the surface of the two samples 24 . The results of the XPS study are consistent with the fact that hydrogen storage in Bi occurs during the electrochemical treatment process.…”

Recent Progress on NiFe‐Based Electrocatalysts for Alkaline Oxygen Evolution

“…Water electrolysis in the alkaline medium requires a more active and robust catalysts, which would be promising for practical application. [ 21–23 ] Recently, NiFe‐based materials are widely investigated as the electrocatalysts in alkaline media due to their abundant reserve and excellent electrocatalytic properties. [ 11,24,25 ] Many interesting strategies such as designing novel morphologies with more active sites, [ 26–28 ] optimizing composition to regulate the electronic structure, [ 29–31 ] and integrating with conductive materials to improve electron transfer are developed to achieve the enhanced activity for water splitting.…”

An efficient method to prepare supported bismuth nanoparticles as highly selective electrocatalyst for the conversion of CO2 into formate

“…In few cases, the reduction step was combined with oxidative calcination treatments to tune the features of the surface oxide layer. 10,21,28 These synthesis procedures require costly multiple steps and/or hazardous reactants (Table S2), thus posing limitations to the industrial upscaling of these electrocatalysts.…”

“…S2 and S3). The high control of the particle size and distribution achieved with our method is notable, particularly when considering that the synthesis methods reported in the literature to prepare Bi-based electrocatalysts either require complex and expensive procedures to produce nanoparticles 12,13,26 or generate materials with micrometric scale at least in one dimension (such as in the case of nanoflakes, 17,21,29 nanosheets, 16,18,19,22,25,27,28 clusters, 11,30 dendrites, 20 needles, 15,24 or tubes 10 ). The loading of Bi in the BiSub@AC-400 electrocatalyst was estimated to be 47 wt% based on ICP-OES analysis and supported by TGA characterisation (Tables S3 and S4, Fig.…”