Facile synthesis of a bismuth nanostructure with enhanced selectivity for electrochemical conversion of CO₂ to formate

Abstract

A facile strategy is adopted to synthesize bismuth nanostructure for efficient CO2 electroreduction to formate.

Boosting Electrochemical Reduction of CO2 at a Low Overpotential by Amorphous Ag‐Bi‐S‐O Decorated Bi0 Nanocrystals

“…Compared to AgBi-200 and Bi-200, AgBi-500 and Bi-500 exhibited much lower Tafel slopes of 104 mV dec À1 and 137 mV dec À1 respectively,w hich illustrates the great enhancement of kinetics activity for eCO 2 RR on samples derived from metal-S-O composites. [13] This difference may reflect the fact that H + in the electrolyte was more difficult to be accessed when using AgBi-200 and Bi-200 for catalyzing eCO 2 RR. [12] ForAgBi-200 and Bi-200, their Tafel slopes were much larger than 118 mV dec À1 , suggesting that the adsorbed CO 2 receiving an electron and combining with H + from the electrolyte to form OCHO* (the adsorbed CO 2 + [H + + e À ]!OCHO*) became the RDS.…”

“…[12] ForAgBi-200 and Bi-200, their Tafel slopes were much larger than 118 mV dec À1 , suggesting that the adsorbed CO 2 receiving an electron and combining with H + from the electrolyte to form OCHO* (the adsorbed CO 2 + [H + + e À ]!OCHO*) became the RDS. [13] This difference may reflect the fact that H + in the electrolyte was more difficult to be accessed when using AgBi-200 and Bi-200 for catalyzing eCO 2 RR. Considering that no Sspecies existed on the surface of AgBi-200 and Bi-200, while in the amorphous part of AgBi-500 and Bi-500, Swould remain, we could infer that it may be Sspecies on the surface of AgBi-500 and Bi-500 that made H + in the electrolyte more accessible and thus greatly enhanced the kinetics activity.Electrolysis in N 2 -saturated 0.1m KOHsolution shows larger current density of AgBi-500 compared to that of AgBi-200 at the applied potentials,w hich means higher H 2 formation rate of AgBi-500, confirming that So nt he surface could accelerate the dissociation of H 2 O( Supporting Information, Figure S24).…”

Continuous Electrochemical Reduction of CO2 to Formate: Comparative Study of the Influence of the Electrode Configuration with Sn and Bi-Based Electrocatalysts

“…According to the literature [ 22 , 34 , 35 ], electrocatalysts of different nature, different electrode configurations, and different electrochemical reactors have been used for studying the electrocatalytic reduction of CO 2 to HCOOH/HCOO − . On the one hand, copper (Cu) [ 36 ], cobalt (Co) [ 37 ], molybdenum (Mo) [ 38 ], lead (Pb) [ 39 , 40 , 41 ], indium (In) [ 42 , 43 , 44 ], palladium (Pd) [ 45 , 46 ], and especially tin (Sn) [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ] and bismuth (Bi) [ 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ] are the most common catalysts investigated for the selective electrochemical reduction of CO 2 to HCOOH/HCOO − . On the other hand, the electrocatalyst can be used in different electrode configurations, such as in the form of a metal plate, a Gas Diffusion Electrode (GDE), or a Catalyst Coated Membrane Electrode (CCME), operating with different electrochemical reactor configurations and operating conditions.…”

Bismuth‐Decorated Silicon Photocathodes for CO2‐to‐Formate Solar‐Driven Conversion

“…Among them, Bi, which has been first introduced through the pioneering research by Komatsu et al in 1995, [13] has the advantages of being non-toxic and inexpensive. Bi-based catalysts deposited on conducting carbon-based electrodes electrochemically reduced CO 2 to formate with high Faradaic efficiency (FE > 87-90 %) in neutral aqueous solutions [14][15][16][17][18][19][20][21][22][23][24][25] while the use of ionic liquids electrolytes rather promoted the formation of CO. [26][27][28][29][30] In this field of CO 2 electrochemical conversion, the use of semiconducting photocathodes instead of non-photoactive traditionally used electrodes (e. g., metals and carbon) could provide a real benefit in terms of energy gain because it allows the electrochemical process to be activated by photogenerated electrons. [31,32] In that context, silicon appears as one of the most promising semiconducting materials owing to its small bandgap (1.1 eV) able not only to harvest photons from a large portion of the solar spectrum but also to encompass the different proton-assisted multielectron reduction potentials for CO 2 .…”

“…in 1995, [13] has the advantages of being non‐toxic and inexpensive. Bi‐based catalysts deposited on conducting carbon‐based electrodes electrochemically reduced CO 2 to formate with high Faradaic efficiency (FE>87–90 %) in neutral aqueous solutions [14–25] while the use of ionic liquids electrolytes rather promoted the formation of CO [26–30] …”