Integrated 3D Open Network of Interconnected Bismuthene Arrays for Energy‐Efficient and Electrosynthesis‐Assisted Electrocatalytic CO₂ Reduction

Abstract

favored product owing to its widespread applications, for example, as a crucial chemical feedstock, a potential hydrogenstorage medium, and a liquid fuel in fuel cells. [4,5] However, traditional industrial technology for preparing formate is constituted of the carbonylation of methanol and then hydrolysis of the methyl formate, which is energy-intensive and limited by the slow reaction rate. [6,7] Compared with traditional technology, CO 2 RR can produce formate under mild conditions with high energy conversion efficiency. [8] Currently, some non-noble metals such as Pb, Sn, In, Bi, etc., are known to be selective for CO 2 reduction to formate. [9][10][11][12] Notably, bismuth (Bi), with the layered structure similar to black phosphorus, has received much attention owing to its earth-abundance, low toxicity, activity, and formate selectivity for CO 2 RR, as well as large energy barrier for the competing hydrogen evolution reaction (HER). [13] Recently, a variety of Bi-based catalysts for CO 2 RR to formate have been investigated. [14,15] Nevertheless, the current Faradaic efficiency (FE formate ) and partial current density (J formate ) for formate production over most of those Bi-based catalysts are still not satisfactory for practical application, due to the insufficient atomic utilization and low intrinsic activity of the active Bi sites. [16] Besides, unlike most metals, Bi is a natural semimetallic element featuring a relatively limited conductivity, which is detrimental to the electrochemical applications. [17] Therefore, it is critical to develop more efficient catalysts for highly active and selective CO 2 conversion to formate with industrial prospect (e.g., FE > 90%, J > 200 mA cm −2 ). [18] Electrocatalytic CO 2 reduction reaction (CO 2 RR) toward formate production can be operated under mild conditions with high energy conversion efficiency while migrating the greenhouse effect. Herein, an integrated 3D open network of interconnected bismuthene arrays (3D Bi-ene-A/CM) is fabricated via in situ electrochemically topotactic transformation from BiOCOOH nanosheet arrays supported on the copper mesh. The resulted 3D Bi-ene-A/CM consists of 2D atomically thin metallic bismuthene (Bi-ene) in the form of an integrated array superstructure with a 3D interconnected and open network, which harvests the multiple structural advantages of both metallenes and self-supported electrodes for electrocatalysis. Such distinctive superstructure affords the maximized quantity and availability of the active sites with high intrinsic activity and superior charge and mass transfer capability, endowing the catalyst with good CO 2 RR performance for stable formate production with high Faradaic efficiency (≈90%) and current density (>300 mA cm −2 ). Theoretical calculation verifies the superior intermediate stabilization of the dominant Bi plane during CO 2 RR. Moreover, by further coupling anodic methanol oxidation reaction, an exotic electrolytic system enables highly energy-efficient and value-added pair-electrosynthesis for ...

Recent progress of Bi-based electrocatalysts for electrocatalytic CO2 reduction

“…FE formate >90%, current density >200 mA cm −2 ), He et al employed a hydrothermal method to yield layered BiOCOOH arrays on the surface of copper mesh (CM), followed by an electrochemical topotactic conversion approach to prepare 3D interconnected bismuthene arrays with an open network (Bi-ene-A/CM, here Bi-ene and A stand for bismuthene and arrays, respectively). 47 The detailed preparation procedures are illustrated in Fig. 4c.…”

Coupling Value‐Added Anodic Reactions with Electrocatalytic CO2 Reduction

“…[30,31,37,[61][62][63][64][65][66][67][68] As mentioned in the Introduction, if an electrocatalyst for selective CO 2 reduction to formate is used in the cathode, the concurrent production of formate can be realized (Figure 3a), eliminating the need for separate downstream purification of products from two sides. [30,31,37,[61][62][63][64][65][66] For example, by using aligned InS nanorods and (oxy)hydroxide@np-Ni 3 P as the cathode and anode catalysts, Zhang et al reached a j total of 50 mA • cm À 2 at a low cell voltage of 2.286 V, with a decrease of 257 mV compared to the conventional system (Figure 3b), indicating the favorable thermodynamics of MOR over OER. [64] Moreover, the differences of cell voltages between them became more pronounced as j total increased (Figure 3c).…”

“…Recently, a wide range of value-added anodic reactions have been studied and coupled with cathodic CO 2 RR. [24,[37][38][39][40][41][42][43] A comprehensive discussion is needed to gather all the initial efforts together and push the coupled system to a more practical level.…”

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

“…P-region transition metals such as Pd, Sn, , Bi, , Pb, and In , exhibit high formate selectivity in the electrochemical reduction of CO 2 . Especially, bismuth-based catalysts (Bi 2 O 3 , , Bi, etc.)…”