Nonnitrogen Coordination Environment Steering Electrochemical CO₂-to-CO Conversion over Single-Atom Tin Catalysts in a Wide Potential Window

Abstract

Replacing conventional metal–N4 moieties with different coordination structures is a promising strategy to tailor the activity and selectivity of single-atom catalysts (SACs). However, for CO2 electroreduction driven by metals that may produce diverse chemical species, such as Tin (Sn), the influences of nonnitrogen coordination environments on the CO2 reduction pathways are unclear. Herein, we report an Sn SAC with a special coordination structure of Sn-C2O2F, which delivers CO as an exclusive CO2 reduction product with a faradaic efficiency higher than 90.0% over a wide potential window (−0.2 to −0.6 V vs the reversible hydrogen electrode) and a peak value of up to 95.2%. The resulting cathodic energy efficiency and current density achieve 70.7% and 186 mA cm–2, respectively. In contrast, formate is predominantly formed on the Sn-N4 site. Theoretical calculations disclose that C and O coordination modulates the adsorption of intermediates, while an Sn-bonded F atom significantly suppresses the hydrogen evolution, thereby facilitating CO2-to-CO conversion. Meanwhile, the CO2-to-HCOO– conversion via O-bound intermediates or direct reaction of absorbed H and dissolved CO2 is prohibited.

P-block tin single atom catalyst for improved electrochemistry in a lithium–sulfur battery: a theoretical and experimental study

“…45,49,50 Novel studies have engineered the coordination environments of the Sn, In and Sb metal-based M–N x sites, and successfully modulated the selectivity and efficiency of the single atom catalysts for CO 2 reduction reaction. 51 Regarding the single metal atom catalysts for Li–S batteries, it is highly instructive to expand the metal catalogue to the p-block metals. High quality catalyst fabrication, electrochemical functionality characterization and an in-depth structure–property relationship study for the p-block single metal catalysts for Li–S electrochemistry are urgently demanded.…”

The Deep Understanding into the Promoted Carbon Dioxide Electroreduction of ZIF‐8‐Derived Single‐Atom Catalysts by the Simple Grinding Process

“…[ 5 ] Among them, ZIF‐8 is widely studied as the template for the SAC synthesis for the easy fabrication and tunability of metal nodes in the structure for the enhanced catalytic performance in many reactions such as HER, [ 6 ] ORR, [ 7 ] and CO 2 RR. [ 8 ] Studies focus on the chemical modifications of the ZIF‐8‐derived SACs, for example, adjusting the metal–N structure in the SACs such as Fe–N, [ 9 ] Ni–N, [ 10 ] Cu–N, [ 11 ] and Co–N, [ 12 ] the combination of two different transition metals to form bimetallic SACs such as Fe–Ni–N–C, [ 13 ] and modifying the SACs with heteroatom dopants such as P [ 14 ] and F. [ 15 ] These chemical variations in the catalysts prove to significantly improve the FE of the CO 2 RR products in ECO 2 RR. [ 16 ] Besides the modification in the chemical state of the ZIF‐8‐derived SACs, the physical properties can also be altered through the chemical modifications.…”

Recent progress of Bi-based electrocatalysts for electrocatalytic CO2 reduction

“…Single-atom Sn electrocatalysts are excluded in the discussion because they may produce CO according to the Sn atomic configurations, due to different electrocatalytic reaction routes. [81][82][83] For example, Ni et al designed Sn-based single-atom catalysts with a coordination configuration of Sn-C 2 O 2 F, which enabled the effective electrocatalytic conversion of CO 2 to CO with a FE value of up to 95.2%. 82 As a consequence, Sn tends to be integrated with Bi to form BiSn bimetallic electrocatalysts for the research community to comprehensively investigate CO 2 RR-associated parameters, performances and product selectivity, but showing lower frequency compared with other types of binary metallic electrocatalysts.…”

“…[81][82][83] For example, Ni et al designed Sn-based single-atom catalysts with a coordination configuration of Sn-C 2 O 2 F, which enabled the effective electrocatalytic conversion of CO 2 to CO with a FE value of up to 95.2%. 82 As a consequence, Sn tends to be integrated with Bi to form BiSn bimetallic electrocatalysts for the research community to comprehensively investigate CO 2 RR-associated parameters, performances and product selectivity, but showing lower frequency compared with other types of binary metallic electrocatalysts. [84][85][86][87][88] Despite all this, recent discoveries with respect to BiSn binary electrocatalysts for the CO 2 RR have been systematically reviewed in this section (Table 2).…”