Selective CO₂ Electromethanation on Surface-Modified Cu Catalyst by Local Microenvironment Modulation

Abstract

Renewable methane synthesized via CO2 electroreduction has the potential to serve as a carbon-neutral medium benefiting from its high energy density. However, challenges remain in achieving high selectivity for electromethanation with low energy input. Here, we found that the adhered ligands on the copper surface can modulate the local microenvironment to realize high rates for methane electrogeneration. The designed glutathione-modified copper electrode exhibited an impressive CO2 to CH4 Faradaic efficiency of 61.7% with a partial current density of 153.7 mA cm–2, which was 35-fold higher than that of pristine copper. Operando Raman spectroscopy experiments suggest that the carboxyl and amino groups of glutathione ligands play a crucial role in regulating intermediate configurations and local proton availability. More broadly, these findings offer routes to alter surface reactivity and create a platform for designing highly selective CO2 electroreduction catalysts.

Asymmetric Low-Frequency Pulsed Strategy Enables Ultralong CO2 Reduction Stability and Controllable Product Selectivity

“…The poor stability of Cu-based materials results from serious degradation mechanisms such as fragmentation, reshaping, and agglomeration, , and the low selectivity is due to the uncontrollable oxidation state of Cu during the CO 2 RR procedure . Many kinds of strategies have been reported to solve these problems, such as controlling the surface structure, − morphology, and oxidation state of the catalysts, doping various elements into the catalysts, optimizing the electrolyte ions and reaction pH, and designing the electrochemical cell. , Although these strategies enhance product selectivity, CO 2 RR stability and affordability still remain challenges.…”

Deciphering Electrolyte Selection for Electrochemical Reduction of Carbon Dioxide and Nitrogen to High‐Value‐Added Chemicals

“…For a long time, researches about electrocatalytic CO 2 reduction reaction (CO 2 RR) and electrocatalytic N 2 reduction reaction (NRR) have been mainly focused on the exploration of electrocatalysts since they improve the reaction rate, efficiency, and selectivity toward desired products. [16][17][18] A large number of publications show that numerous efforts have been made to design and construct the active sites on the surface of electrocatalysts to enhance the performance of CO 2 RR and NRR, including the regulation of crystal facets, [19][20][21] surface morphology, [22][23][24][25] particle size, [26][27][28] oxidation state, [29,30] and heteroatom doping. [31][32][33] Although these regulation methods have got some obvious advance, they cannot overcome the fatal flaws of overall electrocatalytic processes, including the low solubility of CO 2 and N 2 in electrolyte, and the competitive hydrogen evolution reaction (HER).…”

Promoting electrocatalytic CO2methanation using a molecular modifier on Cu surfaces

“…30 The S–H bands of BDT at 930.5 cm −1 and 2538.8 cm −1 disappeared in Cu NPs-BDT, which suggested that benzenethiol was attached to the Cu surface via a Cu–S bond. 30,31 S 2p XPS (Fig. 1c) of Cu NPs-BDT showed peaks at 165.3 eV and 164.1 eV attributed to the C–S bond and peaks at 162.7 eV and 163.9 eV corresponded to the Cu–S bond, consistent with FT-IR spectroscopy.…”

“…1c) of Cu NPs-BDT showed peaks at 165.3 eV and 164.1 eV attributed to the C–S bond and peaks at 162.7 eV and 163.9 eV corresponded to the Cu–S bond, consistent with FT-IR spectroscopy. 31,32 Cu 2p XPS (Fig. S7†) results showed the presence of Cu 0 /Cu + species.…”