CO₂RR-to-CO Enhanced by Self-Assembled Monolayer and Ag Catalytic Interface

Abstract

Electroreduction of CO 2 to fuels (e.g., CO) catalyzed by transition metal catalysts is a promising approach to mitigate global warming issues, but it has limitations of low catalytic activity and high applied potential. The interface between self-assembled monolayers (SAMs) and transition metal surfaces could potentially stabilize the active surfaces and create bifunctional catalytic sites to improve the catalytic performance. Herein, we proposed a new type of electrocatalyst, 4mercaptobenzonitrile (4-MBN) SAMs-modulated Ag, as an example to enhance the reaction of CO 2 -to-CO over Ag. We first examined the stabilization effect of 4-MBN SAMs over Ag and then evaluated the CO 2to-CO over 4-MBN/Ag (i.e., Ag(111), Ag(100), and Ag(211)) using density functional theory calculations. Our results showed that 4-MBN SAMs strongly bonded over Ag(211), and hence stabilized the Ag step site, the potential active site for the CO 2 -to-CO reaction. Notably, 4-MBN SAMs introduced new organic active sites. The new organic active sites mitigated the formation free energy of the key intermediate *OCOH (the potential rate-limiting step of CO 2 -to-CO) via a strong C−N bond up to 0.65 eV, compared to that of the pristine Ag surface. Consequently, CO 2 -to-CO can possibly occur at a lower applied potential at the SAM/Ag interface than that over the pristine Ag surface. Overall, our theoretical work demonstrates that a SAMs/metal interface stabilizes step sites, creates dual organic−inorganic active sites, modifies surface electronic properties, and provides a new strategy for the electrocatalyst design with potentially enhanced energy efficiency.

Constructing Ionic Interfaces for Stable Electrochemical CO2 Reduction

“…Until now, certain metals have shown reasonable selectivity toward specific catalytic products in the CO 2 reduction reaction (CO 2 RR). For example, silver (Ag), gold (Au), and zinc (Zn) catalysts exhibit high selectivity for converting CO 2 into carbon monoxide (CO). − Indium (In), bismuth (Bi), and tin (Sn)-related catalysts are capable of catalyzing CO 2 to formic acid (HCOOH). − Copper (Cu) is widely studied for its ability to produce multicarbon products. − However, achieving high selectivity and productivity of the CO 2 RR is still challenging due to the competing hydrogen evolution reaction (HER) and the complex reaction pathways involved in the formation of multicarbon products. To address these challenges, high-alkaline electrolytes have become a mainstream choice, because the HER is more active in acidic environments.…”

Ag1+ incorporation via a Zr4+-anchored metalloligand: fine-tuning catalytic Ag sites in Zr/Ag bimetallic clusters for enhanced eCO2RR-to-CO activity

“…The electrochemical reduction of CO 2 (eCO 2 RR) stands as a highly promising pathway for the conversion of CO 2 into valuable chemical fuels. 1,2 Among the diverse range of potential electrocatalysts, silver (Ag)-based nanomaterials have garnered significant attention due to their remarkable selectivity in producing CO. 3–6 Despite notable advancements in the synthesis of monodisperse Ag nanoparticles, accurately characterizing their structural attributes and identifying catalytic Ag sites remains a formidable challenge. 7,8 This limitation hampers the attainment of a comprehensive understanding of the intricate relationship between structure and activity, consequently impeding the overall progress in this research field.…”

Enhanced CO2 Reactive Capture and Conversion Using Aminothiolate Ligand–Metal Interface

“…Another advantage of surface ligands in electrocatalysis is that well-designed tail groups of the surface ligands could directly interact with the reactant CO 2 . Due to the amine group’s capability to capture CO 2, − it is usually designed as the tail group of the organic ligands for CO 2 capture and activation. − Sandru et al designed a high-solubility and fast-diffusion membrane by growing an ultrathin amine-containing surface layer on a supported high-permeability polymer thin film for CO 2 capture. Taken together, modified Cu catalysts using organic ligands with a sulfur headgroup and an amine tail group (i.e., aminothiolates) could potentially enhance CO 2 reactive capture and conversion.…”