Interface‐Induced Electrocatalytic Enhancement of CO₂‐to‐Formate Conversion on Heterostructured Bismuth‐Based Catalysts

Abstract

greenhouse gas effect and to simultaneously convert CO 2 to value-added industrial products. [1][2][3][4][5] However, the inertness of CO 2 molecule, the sluggish multi-electron transfer kinetics, and the competitive hydrogen evolution reaction (HER) during CO 2 RR result in the high overpotential (η) to various degrees, which jeopardizes CO 2 RR performance. [6,7] Therefore, it is highly desirable to develop the electrocatalysts that are capable of compromising the above impediments and simultaneously achieving the optimal CO 2 RR performance through specific optimization process.Formic acid (HCOOH) or formate, as an important liquid product from CO 2 RR, has been widely employed as chemical intermediates in various industrial processes. [8] The common industrial manufacture of HCOOH involves the carbonylation of methanol prior to the hydrolyzing of methyl formate. This process is performed in the liquid phase at elevated pressure, which is an energy-intensive and high-cost process. [9] In contrast, CO 2 RR to HCOOH requires a quite mild reduction condition. Currently, some metal-based materials (e.g., Sn, [10][11][12] Pb, [13][14][15] In, [16,17] and Cd [18,19] ) have been studied for HCOOH formation during CO 2 RR because of their suitable binding energy for the intermediate HCOO*. [20,21] However, the high cost and toxicity of these heavy metals (e.g., Pb, Cd, In, etc.) preclude their scalability. Remarkably, Bi-based materials have attracted much attention owing to their low toxicity, earth-abundance, and good selectivity toward formate formation. Various features of Bi-based materials, such as size, morphology, and electrocatalysts with conductive support, have been widely investigated to achieve enhanced electrocatalytic activity and selectivity. [22][23][24] Nevertheless, their low current density (j) and high overpotential are still the bottlenecks that restrict their practical applications at industrial level. [25,26] Therefore, it is of great importance to fabricate the highly effective and stable Bi-based electrocatalysts, to explore the associated reaction mechanism in order to achieve an improved selectivity toward formate.The complicated multi-electron transfer steps during CO 2 RR suggest the importance of charge transfer ability of electrocatalyst. [27,28] Various studies on Bi-based electrocatalysts, including the construction of Bi 2 O 3 nanosheets (NSs) on multi-channel carbon matrix support, [29] the fabrication of Bi 2 O 3 @C derived Electrochemical CO 2 reduction reaction (CO 2 RR) is a promising approach to convert CO 2 to carbon-neutral fuels using external electric powers. Here, the Bi 2 S 3 -Bi 2 O 3 nanosheets possessing substantial interface being exposed between the connection of Bi 2 S 3 and Bi 2 O 3 are prepared and subsequently demonstrate to improve CO 2 RR performance. The electrocatalyst shows formate Faradaic efficiency (FE) of over 90% in a wide potential window. A high partial current density of about 200 mA cm −2 at −1.1 V and an ultralow onset potential with formate FE of ...

Bi catalysts supported on GaN nanowires toward efficient photoelectrochemical CO2 reduction

“…For instance, charge transfer at the interface between two different Bi-based materials led to optimizing the binding energy of adsorbates and lowered the thermodynamic energy barrier. 53,54 The effect of the semiconductor/cocatalyst interface on catalytic performance, however, has been rarely investigated even though there have been many reports of the PEC CO 2 RR to HCOOH by integrating photocathodes and cocatalysts (Table S2 †). Thermodynamically feasible production of HCOOH by Bi 2 O 3 -GaN binary system compared to each material of Bi 2 O 3 and GaN revealed that the design rule of heterogeneous catalysis can be applied to PEC reactions.…”

Revealing the Behavior of Interfacial Water in Te-Doped Bi via Operando Infrared Spectroscopy for Improving Electrochemical CO2 Reduction

“…(e) Long-term test and the corresponding FE COOH of Bi­(Te) 2 /NCNSs at −0.90 V (vs RHE). (f) Advanced Bi-based catalysts reported in recent years, FE HCOOH > 90% potential range and maximum j HCOOH in the potential range: Bi NS (ref ), Bi 2 S 3 –Bi 2 O 3 (ref ), Bi–Sn aerogel (ref ), Bi@Sn (ref ), N–Bi (ref ), Bi 2 O 3 NSs (ref ), and Bi-NC (ref ). Inset in (a): LSV curves of Bi­(Te) 2 /NCNSs in Ar-saturated and CO 2 -saturated KHCO 3 solutions.…”

Galvanic‐Cell Deposition Enables the Exposure of Bismuth Grain Boundary for Efficient Electroreduction of Carbon Dioxide

“…Compared to the previously reported Bi-based electrocatalysts those operated at the potential within −1.0 V in the H-type cell, the formate production rates in our study are competitive with much less synthesis time (Figure 3d; Table S4, Supporting Information). [16,20,26,27,34,39] Moreover, the GC-D/Bi exhibited a low Tafel slope of 99.8 mV dec -1 and outperformed TE-D/Bi (114.9 mV dec -1 ), illustrating the more favorable CO 2 RR kinetics on GC-D/Bi due to the incorporation of grain boundaries (Figure 3e). The electrochemical impedance spectroscopy (EIS) measurements in Figure S12 also imply a faster electron transfer rate on GC-D/Bi compared to that on TE-D/Bi.…”