Dendritic Ag Electrocatalyst with High Mass-Specific Activity for Zero-Gap Gas-Fed CO₂ Electroreduction

Abstract

Electrodeposited silver catalyst is attractive compared to commercially available silver nanoparticles because it allows for the investigation of catalyst morphology and crystallography on the performance of CO2 electrolyzer for the conversion of CO2 to CO. In this work, Ag electrodes with different Ag structures varying from polycrystalline to dendrite were fabricated by controlling different electrodeposition parameters: deposition voltage, ethylenediamine additive and ammonium sulfate concentration, and time of deposition. The electrode performance was evaluated in a zero-gap, gas-fed, polymer electrolyte membrane-based cell. The highest mass-specific activity of 362 mA·mgAg –1 and a CO selectivity of 94% at a cell potential of 3 V were achieved for dendritic Ag catalyst (0.29 mg·cm–2) that possessed the maximum (220)/(111) facet ratio, as determined by X-ray diffraction. The long-term durability test on the electrode demonstrated a robust performance after 100 h of CO2 reduction at a 3 V cell voltage.

Membrane Electrode Assembly for Electrocatalytic CO2 Reduction: Principle and Application

“…Alihosseinzadeh et al. have prepared dendritic Ag catalyst via electrodeposition, which exhibited 362 mA mg Ag −1 and 94 % CO selectivity at 3 V [90] . Lee et al.…”

“…Ag exhibits broader prospect in MEA application. Alihosseinzadeh et al have prepared dendritic Ag catalyst via electrodeposition, which exhibited 362 mA mg Ag À 1 and 94 % CO selectivity at 3 V. [90] Lee et al have synthesized coral-shaped Ag catalyst as follows: Ag catalyst layers were firstly deposited onto a carbon paper substrate via electronbeam evaporation technique, then the electrode was oxidized in Ar-saturated 0.1 M KCl solution to achieve AgCl electrode. Finally the AgCl electrode was reduced in CO 2saturated 0.1 M KHCO 3 solution to obtain the target sample.…”

Effects of Iron Species on Low Temperature CO2 Electrolyzers

“…Impressive selectivity has been demonstrated for catalysts that form dominantly formic acid/formates (> 95 %) or CO (> 90 %). [3,4,8,9] High operating current densities exceeding 1 Acm À 2 have even been attained at lower faradaic efficiency. [10][11][12] The lack of longterm stability, i.e.…”

Copper-Nanowires Incorporated with Silver-Nanoparticles for Catalytic CO2 Reduction in Alkaline Zero Gap Electrolyzer

“…Carbon capture and utilization play important roles in reducing the impact of CO 2 on climate change. Among various technologies, CO 2 electroreduction has attracted much interest in recent years due to its potential for directly converting CO 2 to a variety of valuable fuels using renewable electricity, such as photovoltaics. − Ideal electrochemical catalysts are pursued with highly catalytic activity, long-term stability, and good selectivity, which are largely dependent on unique nanomaterial development. ,,− In addition, highly efficient electrochemical reactors are required to convert CO 2 to usable fuels at an industrial scale production rate ( j > 100 mA/cm 2 ). ,− In the present research, we addressed these two factors for highly efficient catalyst development and electrochemical reactor design.…”

“…Networked nanomaterials are promising CO2RR environments because they have large active surface areas and unique nanostructures encouraging fast mass transfer, electron transfer, and ion transfer, in addition to high electrochemical activity and stability. One-dimensional (1D) materials, such as nanotubes and nanowires, are the building blocks to form nanonetworks, which connect metal-nanoparticles to further composite of a 2D or a 3D structure for electrochemical applications, such as batteries, fuel cells, and water electrolysis. − Metal-nanowires have become common materials to be used as a catalyst for CO 2 reduction reaction (CO2RR), where an H-type electrolytic cell or flow-electrolyte cell is used as the reactor. − Different from the H-type or flow-type cell reactors, the zero-gap cell (as electrolyte membrane, <40 μm) has been recognized as the highest efficiency reactor for electrochemical reduction of carbon dioxide, potentially meeting the electrolysis rate requirements of industrial production. ,− We designed a catalytic nanonetwork by incorporating Ag-nanoparticles into copper-nanowires to realize the highest catalytic activity, stability, electric conductivity, and fast mass transfer.…”