Hybrid Organic‐Inorganic Heterogeneous Interfaces for Electrocatalysis: A Theoretical Study of CO₂ Reduction to C₂

Abstract

Hybrid organic-inorganic heterogeneous catalytic interfaces, where traditional catalytic materials are modified with selfassembled monolayers (SAMs), create promising features to control a wide range of catalytic processes through the design of dual organic-inorganic active sites and the induced confinement effect. To provide a fundamental insight, we investigated CO 2 electroreduction into valuable C 2 chemicals (CO 2 RR-to-C 2 ) over SAM-modulated Cu. Our theoretical results show that 1/4 monolayer aminothiolates improve the stability, activity and selectivity of CO 2 RR-to-C 2 by: (1) decreasing surface energy to suppress surface reconstruction; (2) facilitating CO 2 activation and CÀ C coupling through dual organic-inorganic (i. e., À NH, Cu) active sites; (3) promoting CÀ C coupling via confinement effects that enlarge the adsorption energy difference between CO* and COH*; (4) inducing local electric fields to Cu surface and changing its dipole moment and polarizability to be in favor of CÀ C coupling under electrode/electrolyte interfacial electric field.

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

“…The SAMs at the examined highest coverage promoted the * OCOH formation via reducing the free energy up to 0.65 eV than the pristine Ag sites. Similar organic active N sites for electrocatalysis of CO 2 RR were also noticed and reported via several works before. ,, …”

“…A homogeneous electric field, <−0.6 V/Å, could be generated at the electrode/electrolyte interface in an electrochemical cell due to the potential drop (∼2 V) within a thin layer (3 to 8 Å). ,, To induce the homogeneous electric field into our model, we used a method developed by Neugebauer and Scheffler. , The method inserts a dipole layer at the middle of the vacuum with different charges at each side of the dipole layer and, thus, induces a homogeneous electric field via polarizing the catalytic surfaces with the opposite charges. − …”

“…Theoretical work has been extensively explored on structure and catalysis of inorganic metal systems, including traditional metal surfaces, metallic derivatives, bimetallic systems, and single atom catalysis. ,− However, the fundamental understanding of the interfacial catalytic reactivity near the SAM-modulated transition metal surface is still limited, ,− hindering the design of such organic–inorganic hybrid catalysts. This work aims to provide theoretical insights into the electronic properties of the surfactant/metal interface and how such an interface could interact with the reaction-related species using a case study of CO 2 RR-to-CO over SAM-modulated Ag.…”

In Situ Reconstruction of Cu–N Coordinated MOFs to Generate Dispersive Cu/Cu2O Nanoclusters for Selective Electroreduction of CO2to C2H4

“…Electrochemical CO 2 reduction provides a promising strategy to convert CO 2 into high-value-added fuels and industrial feedstocks. , Up to now, the known products of CO 2 electroreduction include CO, HCOOH, CH 4 , C 2 H 4 , C 2 H 5 OH, etc. − Compared with C 1 products, C 2+ products have higher energy density and higher market value. − It is well known that great breakthrough has been made in the design and research of electroreduction catalysts to obtain hydrocarbons, but the reaction is still limited by the poor C 2+ selectivity and low activity. − Among the developed and used electrocatalysts, Cu-based materials are the most promising for the synthesis of multi-carbon products in the CO 2 RR because of the moderate binding energy of the *CO intermediate, which provides favorable conditions for the C–C coupling step. − However, the low selectivity and activity of C 2+ products and low current densities limit the wide application of Cu-based catalysts, which are still worthy of further study.…”

Trends in Electrocatalysis: The Microenvironment Moves to Center Stage

“…Using multiscale simulations, Che found that the presence of an organic layer at an electrode/electrolyte interface can lead to significant alterations in the local electric field, dipole moments, and polarizability of the system, which may enhance the catalytic performance of CO 2 reduction to C 2 species as compared to a bare metal. 32 Impact of Mass Transport and Potential Variation on Electrocatalytic Reactions. Depending on the ease of transport, the local concentration of reagents at the reaction plane (where the catalytic reaction takes place) is substantially different from that in the bulk.…”