Hydroxypillar[5]arene‐Confined Silver Nanocatalyst for Selective Electrochemical Reduction of CO₂ to Ethanol

Abstract

CO is usually the dominant product on silver-based catalysts in electrochemical CO 2 reduction reaction (CO 2 RR) possibly due to weak *CO adsorption. In this report, a hydroxypillar[5]arene-extended porous polymer-confined silver catalyst (PAF-PA5-Ag-0.8) for electrochemical CO 2 RR which can selectively produce ethanol with a maximum Faradaic efficiency of 55% at 11 mA cm −1 is described. The study reveals that the hydroxypillar[5]arene-confined Ag clusters are the active sites for ethanol formation. Moreover, temperature-programmed desorption measurements demonstrate an enhanced adsorption strength of CO* on PAF-PA5-Ag-0.8 compared with that on commercial Ag nanoparticles, which is favored by the C-C coupling to form ethanol. The density functional theory study indicates that the confined Ag clusters in PAF-PA5-Ag-0.8 contribute to high C 2 selectivity in CO 2 RR through facilitating *COOH formation, stabilizing *CO intermediates, and inhibiting hydrogen evolution. This work provides a new design strategy by modulating *CO adsorption strength on non-copper electrocatalysts in converting CO 2 into "green" C 2 products.

Constructing a Stable Built-In Electric Field in Bi/Bi2Te3 Nanowires for Electrochemical CO2 Reduction Reaction

“…Converting CO 2 into value-added chemicals or fuels is an appealing method for reducing CO 2 emissions and thereby achieving carbon neutrality. − Nevertheless, the inertness and thermodynamic stability of CO 2 severely constrain its conversion efficiency. Electroreduction CO 2 (CO 2 RR) has attracted substantial attention from researchers due to its high conversion efficiency, mild reaction conditions, and elevated energy efficiency. − The specific products formed depend on the number of protons, electrons, and reduction pathways involved, as the CO 2 RR is a multiproton-coupled and multielectron-transfer processes. , By altering the catalytic conditions or reduction pathways, different surface-bound species can generate corresponding reaction intermediates, leading to the formation of different carbon-containing products such as carbon monoxide (CO), formic acid (HCOOH), methane (CH 4 ), and so on. − HCOOH, revered as a high-value CO 2 electroreduction product, is an important raw material in the pharmaceutical and chemical industries, making it one of the most economically viable products in the CO 2 RR process. − In the electrochemical reaction mechanism, HCOOH requires minimal electron transfer during the electroreduction process, which not only simplifies the reduction of CO 2 to HCOOH but also allows for its subsequent conversion into other raw materials such as hydrogen (H 2 ), CO, and methanol (CH 3 OH) through simple catalytic reactions to meet various industrial production needs. − Therefore, the rational design of catalysts and reduction pathways is crucial to the selectivity and yield of the products.…”

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

“…, ethylene, ethanol, acetic acid, and n -propanol) possess higher energy densities and economic value and can be further utilized as feedstocks for the synthesis of long-chain hydrocarbon fuels. 13–17 Currently, *CO dimerization and *CO hydrogenation are believed to be the main C–C coupling pathways to realize the evolution of C 2+ products, while the rate-determining steps of C 2+ product synthesis can be attributed to the initial activation of CO 2 molecules. 18 Optimizing the *CO binding strength and the subsequent proton transfer-based formation of hydrogenated groups ( e.g.…”

Silver Nanoparticle Sensor Array-Based Meat Freshness Inspection System

“…Ag NPs were synthesized by using polymers as both surface ligands and reductants, with the addition of small amounts of small molecular ligands as co-reductants. When polymers and small molecule ligands are integrated, combinatorial or synergistic effects may occur and impart new physical or chemical properties to Ag NPs (e.g., colloidal stability [27], mechanical [28], optical emission [29], and catalytic activity [30]).…”