Operando Spectroscopic Analysis of Axial Oxygen-Coordinated Single-Sn-Atom Sites for Electrochemical CO2 Reduction.

Sn-based materials have been demonstrated as promising catalysts for the selective electrochemical CO2 reduction reaction (CO2RR). However, the detailed structures of catalytic intermediates and the key surface species remain to be identified. In this work, a series of single-Sn-atom catalysts with well-defined structures is developed as model systems to explore their electrochemical reactivity toward CO2RR. The selectivity and activity of CO2 reduction to formic acid on Sn-single-atom sites are shown to be correlated with Sn(IV)-N4 moieties axially coordinated with oxygen (O-Sn-N4), reaching an optimal HCOOH Faradaic efficiency of 89.4% with a partial current density (jHCOOH) of 74.8 mA·cm-2 at -1.0 V vs reversible hydrogen electrode (RHE). Employing a combination of operando X-ray absorption spectroscopy, attenuated total reflectance surface-enhanced infrared absorption spectroscopy, Raman spectroscopy, and 119Sn Mössbauer spectroscopy, surface-bound bidentate tin carbonate species are captured during CO2RR. Moreover, the electronic and coordination structures of the single-Sn-atom species under reaction conditions are determined. Density functional theory (DFT) calculations further support the preferred formation of Sn-O-CO2 species over the O-Sn-N4 sites, which effectively modulates the adsorption configuration of the reactive intermediates and lowers the energy barrier for the hydrogenation of *OCHO species, as compared to the preferred formation of *COOH species over the Sn-N4 sites, thereby greatly facilitating CO2-to-HCOOH conversion.

[1]  D. Sinton,et al.  High carbon utilization in CO2 reduction to multi-carbon products in acidic media , 2022, Nature Catalysis.

[2]  Jingguang G. Chen,et al.  Tuning Reaction Pathways of Electrochemical Conversion of CO2 by Growing Pd Shells on Ag Nanocubes. , 2022, Nano letters.

[3]  L. Ricardez‐Sandoval,et al.  Nano-crumples induced Sn-Bi bimetallic interface pattern with moderate electron bank for highly efficient CO2 electroreduction , 2022, Nature Communications.

[4]  Yuhan Sun,et al.  Enhanced CO2 electroreduction to formate over tin coordination polymers via amino-functionalization , 2022, Journal of Power Sources.

[5]  Charles E. Creissen,et al.  Keeping sight of copper in single-atom catalysts for electrochemical carbon dioxide reduction , 2022, Nature Communications.

[6]  M. Zachman,et al.  Atomically Dispersed Dual-Metal Site Catalysts for Enhanced CO2 Reduction: Mechanistic Insight into Active Site Structures. , 2022, Angewandte Chemie.

[7]  Min Gyu Kim,et al.  Exploring dopant effects in stannic oxide nanoparticles for CO2 electro-reduction to formate , 2022, Nature Communications.

[8]  D. Astruc,et al.  Electrochemical CO2 reduction (CO2RR) to multi-carbon products over copper-based catalysts , 2022, Coordination Chemistry Reviews.

[9]  V. Thoi,et al.  Guiding CO2RR Selectivity by Compositional Tuning in the Electrochemical Double Layer. , 2022, Accounts of chemical research.

[10]  Cheng Lian,et al.  Engineering the Local Microenvironment over Bi Nanosheets for Highly Selective Electrocatalytic Conversion of CO2 to HCOOH in Strong Acid , 2022, ACS Catalysis.

[11]  Karen Chan,et al.  Unified mechanistic understanding of CO2 reduction to CO on transition metal and single atom catalysts , 2021, Nature Catalysis.

[12]  Minrui Gao,et al.  Stabilizing indium sulfide for CO2 electroreduction to formate at high rate by zinc incorporation , 2021, Nature Communications.

[13]  Mengxin Chen,et al.  Dynamic Restructuring of Cu-Doped SnS2 Nanoflowers for Highly Selective Electrochemical CO2 Reduction to Formate. , 2021, Angewandte Chemie.

[14]  Jianping Xiao,et al.  Copper-catalysed exclusive CO2 to pure formic acid conversion via single-atom alloying , 2021, Nature Nanotechnology.

[15]  Jian-feng Li,et al.  Dynamic Behavior of Single-Atom Catalysts in Electrocatalysis: Identification of Cu-N3 as an Active Site for the Oxygen Reduction Reaction. , 2021, Journal of the American Chemical Society.

[16]  Wenbin Wang,et al.  In Situ Phase Separation into Coupled Interfaces for Promoting CO2 Electroreduction to Formate over a Wide Potential Window. , 2021, Angewandte Chemie.

[17]  Hailiang Wang,et al.  Heterogeneous Molecular Catalysts of Metal Phthalocyanines for Electrochemical CO2 Reduction Reactions. , 2021, Accounts of chemical research.

[18]  B. Han,et al.  Boosting CO2 Electroreduction over cadmium single atom catalyst via tuning axial coordination structure. , 2021, Angewandte Chemie.

[19]  Jun Huang,et al.  Cu-Based Nanocatalysts for CO2 Hydrogenation to Methanol , 2021 .

[20]  W. Jaegermann,et al.  Influence of the Metal Center in M–N–C Catalysts on the CO2 Reduction Reaction on Gas Diffusion Electrodes , 2021 .

[21]  Shiguo Zhang,et al.  Nonnitrogen Coordination Environment Steering Electrochemical CO2-to-CO Conversion over Single-Atom Tin Catalysts in a Wide Potential Window , 2021 .

[22]  Jinhui Hao,et al.  Efficient electrocatalytic reduction of CO2 to HCOOH by bimetallic In-Cu nanoparticles with controlled growth facet , 2021, Applied Catalysis B: Environmental.

[23]  B. Jia,et al.  Engineering Bi-Sn Interface in Bimetallic Aerogel with 3D Porous Structure for Highly Selective Electrocatalytic CO2 Reduction to HCOOH. , 2021, Angewandte Chemie.

[24]  Wenfu Xie,et al.  NiSn Atomic Pair on Integrated Electrode for Synergistic Electrocatalytic CO2 Reduction. , 2020, Angewandte Chemie.

[25]  W. Xu,et al.  Identification of the Electronic and Structural Dynamics of Catalytic Centers in Single-Fe-Atom Material , 2020, Chem.

[26]  X. Sun,et al.  Recent Advances in MOF‐Derived Single Atom Catalysts for Electrochemical Applications , 2020, Advanced Energy Materials.

[27]  Haotian Wang,et al.  Electrochemical CO2 reduction to high-concentration pure formic acid solutions in an all-solid-state reactor , 2020, Nature Communications.

[28]  J. Rossmeisl,et al.  P-block single-metal-site tin/nitrogen-doped carbon fuel cell cathode catalyst for oxygen reduction reaction , 2020, Nature Materials.

[29]  Jianping Xiao,et al.  Unveiling hydrocerussite as an electrochemically stable active phase for efficient carbon dioxide electroreduction to formate , 2020, Nature Communications.

[30]  A. Krasheninnikov,et al.  Synergistic electroreduction of carbon dioxide to carbon monoxide on bimetallic layered conjugated metal-organic frameworks , 2020, Nature Communications.

[31]  K. Artyushkova,et al.  Volcano Trend in Electrocatalytic CO2 Reduction Activity over Atomically Dispersed Metal Sites on Nitrogen-Doped Carbon , 2019, ACS Catalysis.

[32]  Yuping Wu,et al.  Advances in Sn-Based Catalysts for Electrochemical CO2 Reduction , 2019, Nano-micro letters.

[33]  Xueping Qin,et al.  Active Sites on Heterogeneous Single-Iron-Atom Electrocatalysts in CO2 Reduction Reaction , 2019, ACS Energy Letters.

[34]  Wei Liu,et al.  Efficient and Robust Carbon Dioxide Electroreduction Enabled by Atomically Dispersed Snδ+ Sites , 2019, Advanced materials.

[35]  De‐Yin Wu,et al.  Promoting electrocatalytic CO2 reduction to formate via sulfur-boosting water activation on indium surfaces , 2019, Nature Communications.

[36]  B. Dietzek,et al.  Resonance Raman Spectro-Electrochemistry to Illuminate Photo-Induced Molecular Reaction Pathways , 2019, Molecules.

[37]  Zhi Wei Seh,et al.  Understanding heterogeneous electrocatalytic carbon dioxide reduction through operando techniques , 2018, Nature Catalysis.

[38]  Jiajian Gao,et al.  Identifying Active Sites of Nitrogen‐Doped Carbon Materials for the CO2 Reduction Reaction , 2018 .

[39]  D. Cullen,et al.  Unveiling Active Sites of CO2 Reduction on Nitrogen-Coordinated and Atomically Dispersed Iron and Cobalt Catalysts , 2018 .

[40]  Stefan Kaskel,et al.  Understanding activity and selectivity of metal-nitrogen-doped carbon catalysts for electrochemical reduction of CO2 , 2017, Nature Communications.

[41]  Hailiang Wang,et al.  Highly selective and active CO2 reduction electrocatalysts based on cobalt phthalocyanine/carbon nanotube hybrid structures , 2017, Nature Communications.

[42]  Wenli Bi,et al.  Operando Analysis of NiFe and Fe Oxyhydroxide Electrocatalysts for Water Oxidation: Detection of Fe⁴⁺ by Mössbauer Spectroscopy. , 2015, Journal of the American Chemical Society.

[43]  Andrew B. Bocarsly,et al.  Mechanistic Insights into the Reduction of CO2 on Tin Electrodes using in Situ ATR-IR Spectroscopy , 2015 .

[44]  B. Curran,et al.  Moessbauer spectra of tin complexes of phthalocyanine and tetraarylporphines , 1970 .