A Core–Shell‐Structured Silver Nanowire/Nitrogen‐Doped Carbon Catalyst for Enhanced and Multifunctional Electrofixation of CO₂

Abstract

Numerous catalysts have been successfully introduced for CO fixation in aqueous or organic systems. However, a single catalyst showing activity in both solvent types is still rare, to the best of our knowledge. We developed a core-shell-structured AgNW/NC700 composite using a Ag nanowire (NW) core encapsulated by a N-doped carbon (NC) shell at 700 °C. Through control experiments and density functional theory calculations, it was confirmed that Ag nanowires acted as the active sites for CO fixation and the uniformly coating of N-doped carbon created a CO -rich environment around the Ag nanowires, which could significantly improve the catalytic activity of Ag nanowires for electrochemical CO fixation. Under mild conditions, up to 96 % faradaic efficiency of CO, 95 % yield of Ibuprofen and 92 % yield of propylene carbonate could be obtained in the electrochemical CO direct reduction, carboxylation and cycloaddition, respectively, using the same AgNWs/NC700 catalyst. These results might provide an alternative strategy for efficient electrochemical fixation of CO .

Core–shell structured catalysts for thermocatalytic, photocatalytic, and electrocatalytic conversion of CO2

“…Similarly, Ag nanowire@N-doped carbon showed an approximate 10-fold higher CO partial current density than Ag nanowires, because increased CO 2 adsorption on the pyridinic N sites on the shell created a CO 2rich region near the CO 2 -RR active Ag sites. 232 Noble metals are inherently more selective for CO formation than transition metals, but there have nonetheless been efforts to explore transition metal-containing catalysts for CO selective CO 2 -RR to lower the cost. Several Cu-containing core-shell catalysts have been reported, and they have surprisingly shown high selectivity for CO at moderate overpotentials.…”

Nitrogen and sulfur dual-doped high-surface-area hollow carbon nanospheres for efficient CO2 reduction

“…In addition, electrochemical active surface area (ECSA) analysis was carried out based on electrochemical double-layer capacitance (Cdl) (Figs. S4(b) and S5) [65]. The Cdl values of SZ-HCN, Z-HCN, S-HCN, and HCN were calculated as 26.81, 24.55, 16.56, and 16.03 mF cm -2 , respectively.…”

Carbon Materials as Cathode Constituents for Electrochemical CO2 Reduction—A Review

“…The N-doped CNFs were synthesized by pyrolysis of electrospun nanofiber mats of heteroatomic polyacrylonitrile (PAN) polymer. Yang et al prepared N-doped carbon fibers with a core of Ag nanowires of 70-80 nm diameter [52]. The objective was to increase the local concentration of CO2 around the Ag nanowires (AgNWs), due to its porous structure.…”

“…Schematic representation of the synthesis of N-doped carbon fibers with a core of Ag nanowires employing a carbonization temperature of 700 • C (AgNWs/NC700). Reproduced with permission from[52]. Copyright Wiley-VCH, 2018.…”