Efficient Electrochemical Reduction of CO₂ to HCOOH over Sub‐2 nm SnO₂ Quantum Wires with Exposed Grain Boundaries

Abstract

Electrochemical reduction of CO 2 could mitigate environmental problems originating from CO 2 emission. Although grain boundaries (GBs) have been tailored to tune binding energies of reaction intermediates and consequently accelerate the CO 2 reduction reaction (CO 2 RR), it is challenging to exclusively clarify the correlation between GBs and enhanced reactivity in nanostructured materials with small dimension (< 10 nm). Now,s ub-2 nm SnO 2 quantum wires (QWs) composed of individual quantum dots (QDs) and numerous GBs on the surface were synthesized and examined for CO 2 RR towardH COOH formation. In contrast to SnO 2 nanoparticles (NPs) with al arger electrochemically active surface area (ECSA), the ultrathin SnO 2 QWs with exposed GBs show enhanced current density (j), an improved Faradaic efficiency (FE) of over 80 %for HCOOH and ca. 90 %for C1 products as well as energy efficiency (EE) of over 50 %i n awide potential window; maximum values of FE (87.3 %) and EE (52.7 %) are achieved.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Nanoporous structured Sn‐MWCNT/Cu electrodes fabricated by electrodeposition–chemical dezincification for catalytic CO2 reduction

“…The valance state of Sn was further confirmed by XPS spectra, and the results are shown in Figures 2B-D, 3 and 4. Based on Figures 2C and 3D-F, it can be seen that the peaks located at 495.5 and 487.2 eV match well with the characteristic peaks assigned to Sn 3d 3/2 and Sn 3d 5/2 , respectively, which clearly confirms the formation of Sn(IV) 29,35 on the electrode surface. Two distinct binding energy peaks at 491.7 and 483.1 eV can be observed in Figures 2C and 3D-F, which correspond to Sn 3d 3/2 and Sn 3d 5/2 , respectively, confirming the presence of the Sn(0) species.…”

“…26,27 For example, a wavy SnO 2 with optimized surface structure was developed that showed good activity toward HCOO − product. 28 Liu et al 29 developed SnO 2 quantum wires with a size below 2 nm as electrocatalyst to catalyze the conversion of ERCO 2 into HCOO − with a Faradaic efficiency (FE HCOO − ) of over 80%, and attributed the higher performance (compared to that of SnO 2 nanoparticles) to the larger electrochemically active surface area. Creating a porous structure is one of the methods to improve the performance of a catalyst, because porous materials have larger specific surface area and electrochemically active surface area than planar materials; also, the porous structure is conducive to the transfer of CO 2 molecules.…”

Optimization Strategies for Selective CO2 Electroreduction to Fuels

“…The adsorption of key intermediates *COOH is therefore enhanced, which switched the RDS from the *COOH formation to the subsequent proton-coupled electron transfer (PCET) step. Likewise, Liu et al [99] developed sub-2 nm SnO 2 quantum wires (QWs) with numerous GBs. GB-rich SnO 2 QWs present higher j than SnO 2 nanoparticles, with a FE HCOOH of more than 80% and an energy efficiency of over 50% in a wide potential window, further verifying the feasibility and flexibility of introducing GBs to boost CO 2 RR activity.…”

Spontaneously Sn Doped Bi/BiOx Core–shell Nanowires Toward High-Performance CO2 Electroreduction to Formate

“…12). This could lead to CO2 enrichment on the local working electrode surface, which is beneficial for CO2 activation and reduction 32,33 . Electrochemical impedance spectroscopy (EIS) analysis further verifies that the Bi/Bi(Sn)Ox NWs catalyst with metallic core-shell structure could generate small internal resistance and rapid charge transfer behavior for a low onset potential and fast CO2 reduction reaction (CO2RR) kinetics ( Supplementary Fig.…”