Aligned InS Nanorods for Efficient Electrocatalytic Carbon Dioxide Reduction

Abstract

Electrochemical CO2 reduction technology can combine renewable energy sources with carbon capture and storage to convert CO2 into industrial chemicals. However, the catalytic activity under high current density and long-term electrocatalysis process may deteriorate due to agglomeration, catalytic polymerization, element dissolution, and phase change of active substances. Here, we report a scalable and facile method to fabricate aligned InS nanorods by chemical dealloying. The resulting aligned InS nanorods exhibit a remarkable CO2RR activity for selective formate production at a wide potential window, achieving over 90% faradic efficiencies from −0.5 to −1.0 V vs reversible hydrogen electrode (RHE) under gas diffusion cell, as well as continuously long-term operation without deterioration. In situ electrochemical Raman spectroscopy measurements reveal that the *OCHO* species (Bidentate adsorption) are the intermediates that occurred in the reaction of CO2 reduction to formate. Meanwhile, the presence of sulfur can accelerate the activation of H2O to react with CO2, promoting the formation of *OCHO* intermediates on the catalyst surface. Significantly, through additional coupling anodic methanol oxidation reaction (MOR), the unusual two-electrode electrolytic system allows highly energy-efficient and value-added formate manufacturing, thereby reducing energy consumption.

Regular hexagonal CuBi nanosheets boost highly efficient CO2reduction to HCOOH in a solid-electrolyte cell

“…5a, the asymmetric stretching vibration peak of CO 2 − (ν as CO 2 − ) was detected at 1540 cm −1 and showed strength fluctuation from −0.4 V to −0.8 V, corresponding to the bidentate adsorption of *OCHO on Cu-BiOON 4 . 37 Meanwhile, the peak at 1380 cm −1 could be assigned to the symmetric stretching vibration (ν s CO 2 − ) during reduction of CO 2 . 38 As reported, ν s CO 2 − represented the intensity of the C–O in *COOH intermediates coordinated with Bi, 39,40 which was much weaker than that of oxygen atoms in *OCHO, indicating that the adsorption of the *OCHO intermediate played a dominant role on the catalyst surface.…”

“…) was detected at 1540 cm −1 and showed strength uctuation from −0.4 V to −0.8 V, corresponding to the bidentate adsorption of *OCHO on Cu-BiOON 4 . 37 Meanwhile, the peak at 1380 cm −1 could be assigned to the symmetric stretching vibration (n s CO 2…”

Coupling Value‐Added Anodic Reactions with Electrocatalytic CO2 Reduction

“…Methanol oxidation reaction (MOR) to generate formate is the simplest and most reported alcohol oxidation reaction to couple with CO 2 RR. The recent developments are summarized in Table 1 [30,31,37,61–68] …”

“…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 [30,31,37,61–66] . For example, by using aligned InS nanorods and (oxy)hydroxide@np‐Ni 3 P as the cathode and anode catalysts, Zhang et al.…”

“…[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).…”