Enhancing Selective Electrochemical CO₂ Reduction by In Situ Constructing Tensile-Strained Cu Catalysts

Abstract

Heteroatom-doped Cu-based catalysts have been found to show not only enhanced activity of electrochemical CO2 reduction reaction (CO2RR) but also the possibility to tune the selectivity of CO2RR. However, the complex and variable nature of Cu-based materials renders it difficult to elucidate the origin of the improved performance, which further hinders the rational design of catalysts. Here, we demonstrate that the activity and selectivity of CO2RR can be tuned by manipulating the lattice strain of Cu-based catalysts. The combined operando and ex situ spectroscopic characterizations reveal that the initial compressively strained Sn-doped CuO catalysts could be converted to tensile-strained Sn/Cu alloy catalysts under reaction conditions. In situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEITAS) and theoretical calculations further show that the tensile-strained Sn/Cu alloy catalysts favor CO formation due to the preponderant adsorption of *CO and much lower adsorption free energies of *COOH, thus effectively suppressing the dimerization process and the production of HCOOH and H2. This work provides a strategy to tune the CO2RR performance of Cu-based catalysts by manipulating the lattice strain.

Tin as a co-catalyst for electrocatalytic oxidation and reduction reactions

“…174 Strain engineering is an attractive strategy to optimize the electrocatalytic performance by adjusting the intrinsic interatomic forces and thus altering the electronic structure of the electrocatalysts. 175 Sn modification of Cu catalysts, in which Sn atoms preferentially occupy the low-coordination sites, improves the CO selectivity and inhibits the HER, 176 considerably lowers the *COOH and *CO intermediate formation energy barriers, and exposes more active sites, leading to a wider potential range and higher current density, 177 thus achieving high CO 2 RR to CO efficiency, low overpotentials, and excellent stability. Examples include Vo-CuO(Sn) nanosheet electrocatalysts containing oxygen vacancies and Sn dopants, 174 Sn-doped Cu 2 O, 178 non-precious Cu–Sn diatomic sites anchored on nitrogen-doped porous carbon (CuSn/NPC), 179 and tensile-strain tin/copper alloy catalysts, e.g.…”

Electrochemical reduction of carbon dioxide to multicarbon (C2+) products: challenges and perspectives

“…2, purple line highlighted pathway). 11,15,16,42,43 Theoretical simulations of *CO dimerization on several copper facets have confirmed the lowest energy barrier on the (100) facet. 44 *CO dimerization is exothermic on the Cu(100) facet but endothermic on the Cu(111) facet.…”

RuO2–CeO2 Lattice Matching Strategy Enables Robust Water Oxidation Electrocatalysis in Acidic Media via Two Distinct Oxygen Evolution Mechanisms

“…Lattice stress strategies that can adjust the d-band center shift and optimize the binding properties of intermediates have been widely used in electrocatalytic systems such as the oxygen reduction reaction and the CO 2 reduction reaction, but they are rarely mentioned in acidic OER systems. It is worth mentioning that the process of forming a heterostructure through lattice matching between RuO 2 and CeO 2 will induce lattice strain, which will also be a complement to the application of lattice stress in acidic OER reaction systems. − Moreover, most reports today focus on the study of a single OER path, with there being a lack of understanding about whether the OER paths at heterojunction interfaces and noninterface RuO 2 sites are the same.…”