Two-Dimensional SnO₂ Nanosheets for Efficient Carbon Dioxide Electroreduction to Formate

Abstract

The electrocatalytic reduction of CO 2 to liquid fuels is a promising strategy to store the intermittent renewable energies into high-value chemicals. Here, two-dimensional SnO 2 nanosheet (∼3 nm in thickness) materials were synthesized using the hydrothermal method and characterized as efficient electrocatalysts for CO 2 reduction to formate. Compared to the monometallic Snbased catalysts, the SnO 2 nanosheet electrodes exhibit a much improved performance. A large current density of 471 mA cm −2 for formate production and a high Faradaic efficiency of 94.2% are simultaneously achieved using a three-compartment microfluidic flow cell electrolyzer. These results set a new record for formate production among monometallic Sn-based catalysts for the CO 2 electroreduction reaction. Density functional theory calculations reveal the intrinsic improvement in the performance by the SnO 2 surface site over the metallic Sn site.

Experimental and theoretical investigation of the tuning of electronic structure in SnO2viaCo doping for enhanced styrene epoxidation catalysis

“…With a Gaussian fit, the Sn 3d spectrum of the Co-SnO 2 can be well fitted into two peaks at 486.5 and 494.9 eV corresponding to Sn 4+ , and the other two peaks at 485.9 and 494.2 eV assigned to Sn 2+ . 48 The presence of a large amount of lower valent Sn 2+ species suggests the transformation between the valence states of Sn and the generation of abundant OV in the doped sample due to the charge imbalance induced by the substitutional doping of Co into the SnO 2 frameworks. 49,50 By estimating the areas that the fitted curves cover, the Sn 2+ /Sn 4+ molar ratio in the Co-SnO 2 is determined to be 0.55, which is prominently larger than that in the P-SnO 2 (0.14).…”

Engineering Sn‐based Catalytic Materials for Efficient Electrochemical CO2 Reduction to Formate

“…Li et al. compared SnO 2 nanosheets and Sn catalysts and found that SnO 2 suppresses CO and H 2 formation by increasing their free energy gaps of the potential limiting step, thus increasing selectivity towards formate [99] …”

Recent Advances in the Catalyst Design and Mass Transport Control for the Electrochemical Reduction of Carbon Dioxide to Formate

“…We have summarized the reported performances in terms of the strategies for enhancing catalytic performance to provide insight into the effects of these strategies ( Figure 11) [10,47,53,61,72,92,93]. The results of the strategy of tailoring the exposed facets can be seen in the difference between Pd catalysts with low-index and high-index facets reported by Klinkova et al The Pd BNPs with high-index facets have an almost identical FE HCOOH and a 1.5-fold larger formate partial current density compared to the low-index-facet Pd NCs.…”