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Title: Mitigating mass transport limitations: hierarchical nanoporous gold flow-through electrodes for electrochemical CO 2 reduction

Journal Article · · Materials Advances
DOI:https://doi.org/10.1039/D1MA00834J· OSTI ID:1829525

The reaction rates for electrochemical CO2 reduction in aqueous electrolytes can be limited by the low concentration and diffusion rate of the reactant CO2. To overcome this limitation, we fabricated and tested hierarchical nanoporous gold (hnpAu) flow-through electrodes that enable pumping CO2 saturated potassium bicarbonate electrolyte directly through the macropores of hnpAu. The hnpAu flow-through electrode was fabricated by ink casting followed by annealing and dealloying to generate a bimodal pore distribution where macropores (5–10 μm) act as flow channels and nanopores (~40 nm) provide high surface area. To minimize local CO2 depletion at the electrolyte–electrode interface we selected flow rates that warranted diffusion lengths exceeding the macropore diameter dimensions. We observed that the CO2 reduction rate increases with increasing flow rate through the electrode, but even for the highest overpotentials and flow rates, less than 20% of the dissolved CO2 was utilized despite the absence of diffusion limitations. We find that the competing hydrogen evolution reaction becomes increasingly suppressed with increasing flow rate, specifically in the low overpotential regime. These observations suggest that, beyond diffusion limitations, the CO2 reduction rate in aqueous electrolytes may become limited by the availability of free reaction sites, and that flowing the electrolyte through the electrode increases the CO2 reduction rate by facilitating the removal of the CO product.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC52-07NA27344
OSTI ID:
1829525
Alternate ID(s):
OSTI ID: 1838259
Report Number(s):
LLNL-JRNL-818910; MAADC9
Journal Information:
Materials Advances, Journal Name: Materials Advances Vol. 3 Journal Issue: 1; ISSN 2633-5409
Publisher:
Royal Society of Chemistry (RSC)Copyright Statement
Country of Publication:
United Kingdom
Language:
English

References (47)

Bioinspired heat exchangers based on triply periodic minimal surfaces for supercritical CO2 cycles journal October 2020
Competition between CO 2 Reduction and Hydrogen Evolution on a Gold Electrode under Well-Defined Mass Transport Conditions journal February 2020
Hydrolysis of Electrolyte Cations Enhances the Electrochemical Reduction of CO 2 over Ag and Cu journal September 2016
Multilayer Electrolyzer Stack Converts Carbon Dioxide to Gas Products at High Pressure with High Efficiency journal June 2019
Competing Effects of pH, Cation Identity, H 2 O Saturation, and N 2 Concentration on the Activity and Selectivity of Electrochemical Reduction of N 2 to NH 3 on Electrodeposited Cu at Ambient Conditions journal November 2020
Mass transport modelling for the electroreduction of CO 2 on Cu nanowires journal December 2017
Effect of mass transfer and kinetics in ordered Cu-mesostructures for electrochemical CO2 reduction journal September 2018
Electrochemical Reduction of Carbon Dioxide at Gold-Palladium Core-Shell Nanoparticles: Product Distribution versus Shell Thickness journal January 2016
Electrochemical Reduction of CO[sub 2] on a Cu Electrode under High Pressure journal January 1994
Towards sustainable fuels and chemicals through the electrochemical reduction of CO 2 : lessons from water electrolysis journal January 2015
Effects of mass transfer on the electrocatalytic CO 2 reduction on Cu journal June 2017
The influence of pH on the reduction of CO and CO 2 to hydrocarbons on copper electrodes journal March 2014
Environment Matters: CO 2 RR Electrocatalyst Performance Testing in a Gas-Fed Zero-Gap Electrolyzer journal October 2020
Using a 3D Porous Flow-Through Electrode Geometry for High-Rate Electrochemical Reduction of CO 2 to CO in Ionic Liquid journal October 2019
Ag–Sn Bimetallic Catalyst with a Core–Shell Structure for CO 2 Reduction journal January 2017
Toward CO 2 Electroreduction under Controlled Mass Flow Conditions: A Combined Inverted RDE and Gas Chromatography Approach journal February 2020
Diffusion coefficients of ferri- and ferrocyanide ions in aqueous media, using twin-electrode thin-layer electrochemistry journal December 1970
Surface Oxide-Derived Nanoporous Gold Catalysts for Electrochemical CO 2 -to-CO Reduction journal August 2019
Advanced manufacturing for electrosynthesis of fuels and chemicals from CO 2 journal January 2021
Bifunctional alloys for the electroreduction of CO 2 and CO journal January 2016
Introductory Guide to Assembling and Operating Gas Diffusion Electrodes for Electrochemical CO 2 Reduction journal February 2019
A Direct Grain-Boundary-Activity Correlation for CO Electroreduction on Cu Nanoparticles journal March 2016
Beyond the catalyst: How electrode and reactor design determine the product spectrum during electrochemical CO2 reduction journal May 2019
Nanostructured nonprecious metal catalysts for electrochemical reduction of carbon dioxide journal June 2016
Electrochemical CO 2 to CO reduction at high current densities using a nanoporous gold catalyst journal November 2020
Scalable fabrication of high activity nanoporous copper powders for electrochemical CO2 reduction via ball milling and dealloying journal March 2021
Standards and Protocols for Data Acquisition and Reporting for Studies of the Electrochemical Reduction of Carbon Dioxide journal May 2018
Grain-Boundary-Dependent CO 2 Electroreduction Activity journal April 2015
Electrochemically converting carbon monoxide to liquid fuels by directing selectivity with electrode surface area journal June 2019
The Central Role of Bicarbonate in the Electrochemical Reduction of Carbon Dioxide on Gold journal March 2017
Selective reduction of CO to acetaldehyde with CuAg electrocatalysts journal January 2020
Highly Dense Cu Nanowires for Low-Overpotential CO2 Reduction journal September 2015
Toward digitally controlled catalyst architectures: Hierarchical nanoporous gold via 3D printing journal August 2018
Surface-chemistry-driven actuation in nanoporous gold journal November 2008
Towards membrane-electrode assembly systems for CO 2 reduction: a modeling study journal January 2019
Effects of electrolyte, catalyst, and membrane composition and operating conditions on the performance of solar-driven electrochemical reduction of carbon dioxide journal January 2015
CO 2 reduction on gas-diffusion electrodes and why catalytic performance must be assessed at commercially-relevant conditions journal January 2019
Modeling the Performance of A Flow-Through Gas Diffusion Electrode for Electrochemical Reduction of CO or CO 2 journal July 2020
Gas-Diffusion Electrodes for Carbon Dioxide Reduction: A New Paradigm journal December 2018
Electrolytic CO 2 Reduction in a Flow Cell journal March 2018
Electrocatalytic and homogeneous approaches to conversion of CO 2 to liquid fuels journal January 2009
Reduction of CO2 and CO to methane on Cu foil electrodes journal April 1988
Determination of the rate constants for the carbon dioxide to bicarbonate inter-conversion in pH-buffered seawater systems journal June 2006
In-situ Raman spectroscopy to elucidate the influence of adsorption in graphene electrochemistry journal March 2017
Electrochemical CO2 reduction: Electrocatalyst, reaction mechanism, and process engineering journal November 2016
Catalysts and Reaction Pathways for the Electrochemical Reduction of Carbon Dioxide journal September 2015
A review of catalysts for the electroreduction of carbon dioxide to produce low-carbon fuels journal January 2014