scholarly journals Analytical modelling of CO2 reduction in gas-diffusion electrode catalyst layers

2021 ◽  
pp. 138987
Author(s):  
J.W. Blake ◽  
J.T. Padding ◽  
J.W. Haverkort
Keyword(s):  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Analytical Modelling ◽  
Catalyst Layers

scholarly journals Investigation of Gas Diffusion Electrode Systems for the Electrochemical CO2 Conversion

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 482
Author(s):  
Hilmar Guzmán ◽  
Federica Zammillo ◽  
Daniela Roldán ◽  
Camilla Galletti ◽  
Nunzio Russo ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Active Sites ◽  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Catalyst Loading ◽  
Co2 Conversion ◽  
Atmospheric Conditions ◽  
Electrochemical Co2 Reduction ◽  
Liquid Products

Electrochemical CO2 reduction is a promising carbon capture and utilisation technology. Herein, a continuous flow gas diffusion electrode (GDE)-cell configuration has been studied to convert CO2 via electrochemical reduction under atmospheric conditions. To this purpose, Cu-based electrocatalysts immobilised on a porous and conductive GDE have been tested. Many system variables have been evaluated to find the most promising conditions able to lead to increased production of CO2 reduction liquid products, specifically: applied potentials, catalyst loading, Nafion content, KHCO3 electrolyte concentration, and the presence of metal oxides, like ZnO or/and Al2O3. In particular, the CO productivity increased at the lowest Nafion content of 15%, leading to syngas with an H2/CO ratio of ~1. Meanwhile, at the highest Nafion content (45%), C2+ products formation has been increased, and the CO selectivity has been decreased by 80%. The reported results revealed that the liquid crossover through the GDE highly impacts CO2 diffusion to the catalyst active sites, thus reducing the CO2 conversion efficiency. Through mathematical modelling, it has been confirmed that the increase of the local pH, coupled to the electrode-wetting, promotes the formation of bicarbonate species that deactivate the catalysts surface, hindering the mechanisms for the C2+ liquid products generation. These results want to shine the spotlight on kinetics and transport limitations, shifting the focus from catalytic activity of materials to other involved factors.

Electrochemically deposited Sn catalysts with dense tips on a gas diffusion electrode for electrochemical CO2 reduction

2020 ◽  
Vol 8 (18) ◽  
pp. 9032-9038 ◽  
Author(s):  
Jinkyu Lim ◽  
Phil Woong Kang ◽  
Sun Seo Jeon ◽  
Hyunjoo Lee
Keyword(s):  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Electrochemical Co2 Reduction ◽  
Electrochemically Deposited

Productivity of formates from electrochemical CO2 reduction was enhanced by using a Sn catalyst with dense tips electrodeposited on a gas diffusion electrode.

scholarly journals In Situ Observation of the pH Gradient near the Gas Diffusion Electrode of CO2 Reduction in Alkaline Electrolyte

2020 ◽  
Vol 142 (36) ◽  
pp. 15438-15444 ◽  
Author(s):  
Xu Lu ◽  
Chongqin Zhu ◽  
Zishan Wu ◽  
Jin Xuan ◽  
Joseph S. Francisco ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Ph Gradient ◽  
Alkaline Electrolyte ◽  
In Situ Observation

scholarly journals Optimizing the use of a “Zero-Gap” Gas Diffusion Electrode Setup for Electrochemical Reduction of CO2

2021 ◽  
Author(s):  
Shima Alinejad ◽  
Jonathan Quinson ◽  
Yao Li ◽  
Ying Kong ◽  
Sven Reichenberger ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Catalyst Layer ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Gas Diffusion Electrode ◽  
Test Bed ◽  
Catalyst Screening ◽  
Electrochemical Co2 Reduction ◽  
Reduction Of Co2 ◽  
Co2 Reduction Reaction

The lack of a robust and standardized experimental test bed to investigate the performance of catalyst materials for the electrochemical CO2 reduction reaction (ECO2RR) is one of the major challenges in this field of research. To best reproduce and mimic commercially relevant conditions for catalyst screening and testing, gas diffusion electrode (GDE) setups attract a rising attention as an alternative to conventional aqueous-based setups such as the H-cell configuration. In particular a zero-gap design shows promising features for upscaling to the commercial scale. In this study, we develop further our recently introduced zero-gap GDE setup for the CO2RR using an Au electrocatalyst as model system and identify/report the key experimental parameters to control in the catalyst layer preparation in order to optimize the activity and selectivity of the catalyst.

scholarly journals Electrochemical Reduction of CO2 on Au Electrocatalysts in a Zero-Gap, Half-Cell Gas Diffusion Electrode Setup: a Systematic Performance Evaluation and Comparison to a H-cell Setup

2021 ◽  
Author(s):  
Shima Alinejad ◽  
Jonathan Quinson ◽  
Gustav K.H. Wiberg ◽  
Nicolas Schlegel ◽  
Damin Zhang ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Gas Diffusion Electrode ◽  
Systematic Evaluation ◽  
Catalyst Loading ◽  
High Dispersion ◽  
Screening Methods ◽  
Synthesis Methods ◽  
Au Nps

Based on H-cell measurements, gold (Au) is one of the most selective catalysts for the CO2 reduction reaction (CO2RR) to CO. To ensure a high dispersion, typically Au small nanoparticles (NPs) are used as catalyst. However, the preparation of small Au NPs based on conventional synthesis methods often requires the use of surfactants such as polyvinylpyrrolidone (PVP). Here, we present a systematic evaluation of the performance of laser-generated, surfactant-free Au NPs for the CO2RR in a gas diffusion electrode (GDE) setup and compare the results to investigations in an H-cell configuration. The GDE setup supplies a continuous CO2 stream at the electrode−electrolyte interface to circumvent CO2 mass transport limitations encountered in conventional H-cells. We investigate the influence of the catalyst loading and the effect of PVP. Comparing the two screening methods, i.e. GDE and H-cell measurements, it is shown that the performance of the same catalyst can be substantially different in the two environments. In the GDE setup without liquid electrolyte-catalyst interface a higher reaction rate, but lower faradaic efficiendy is determined. Independent of the setup, the presence of PVP favours the hydrogen evolution reaction (HER), however, in the GDE setup PVP is more detrimental for the performance than in the H-cell.

scholarly journals (ECS 234th) Pulsed Electrodeposition of Gas-Diffusion Electrocatalysts for CO2 Reduction

2018 ◽  
Author(s):  
Brian Skinn ◽  
DAN WANG ◽  
Rajeswaran Radhakrishnan ◽  
Timothy Hall ◽  
E Jennings Taylor ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Gas Phase ◽  
Current Density ◽  
Co2 Reduction ◽  
Gas Diffusion ◽  
Reduction Reaction ◽  
Pt Catalyst ◽  
Catalyst Layers ◽  
Co2 Electroreduction ◽  
Catalyst Utilization

The performance of electrocatalysts for the electrochemical carbon dioxide (CO2) reduction reaction (eCO2RR) is largely dependent on the ability to efficiently deliver CO2 to the active sites. A variety of reactor configurations have been explored in the literature that can be broadly classified as based on either liquid- or gas-phase reactant delivery. These configurations utilize a range of electrode types including metal plates, meshes, packed granules, and gas diffusion electrodes (GDEs) [1]. Amongst these methods, the use of gas-phase reactor designs employing GDEs enables a dramatic increase in current density (typically an order of magnitude or larger) over liquid-phase reactor designs, where the low solubility and aqueous diffusivity of CO2 result in severe mass transport limitations.However, the performance of GDEs in various CO2 electroreduction processes can be hampered by poor catalyst utilization and transport limitations within the catalyst layer. At higher catalyst loadings (thicker catalyst layers), which are desirable for high production rates, conversion efficiencies drop and undesirable side product formation (both from hydrogen evolution and diversion of carbon to alternative reaction pathways) increases due to reactant starvation. Reducing particle size typically enhances both catalyst utilization and activity per unit mass. This, in turn, may enable thinner catalyst layers, mitigating or avoiding such decreases in product selectivity. While synthesis methods exist for generating smaller (< 10 nm) particles, these particles must still be deposited on a gas-diffusion layer (GDL) substrate such that ionic and electronic contact can be maintained with the electrolyte and GDL, respectively.Previous work directed towards platinum (Pt) catalyst utilization in polymer electrolyte fuel cell GDEs demonstrated an “electrocatalyzation” (EC) approach that used pulse and pulse-reverse electrodeposition to obtain highly dispersed and uniform Pt catalyst nanoparticles (~5 nm) [2-4]. Moreover, since the catalyst was electroplated through an ionomer layer onto the bare GDL, the formed nanoparticles were inherently in both electronic and ionic contact within the GDE and, consequently, utilization was enhanced. Specifically, for the oxygen reduction reaction, the electrodeposited catalyst exhibited equivalent performance at 0.05 mg/cm2 loading compared to a conventionally prepared GDE with a loading of 0.5 mg/cm2 [4].This talk will discuss the electrodeposition of tin (Sn) and copper (Cu) onto both commercially-available and custom-fabricated GDLs through an EC process, and the electrocatalysis performance of these catalysts as compared to state-of-the-art Sn and Cu nanoparticle catalysts (75-150 nm) prepared by spray-coating. Testing in a custom flow-cell electroreactor has demonstrated that the EC GDEs exhibit electrocatalytic performance comparable or superior to both literature reports and the spray-painted catalysts. Further, clear effects of the pulsed-waveform EC parameters on product distribution and total current density will be highlighted. Preliminary work toward development of GDLs robust against electrolyte saturation/penetration over many hours of operation will also be discussed. In summary, the highly scalable EC approach appears promising for fabricating active catalytic layers directly onto GDL substrates for carbon dioxide reduction applications.References[1] I. Merino-Garcia, E. Alvarez-Guerra, J. Albo, A. Irabien, Chemical Engineering Journal, 305 (2016) 104-120.[2] M. E. Inman, E.J. Taylor, in, U.S. Patent No. 6,080,504, 2000.[3] N .R.K. Vilambi Reddy, E. B. Anderson, E.J. Taylor, in, U.S. Patent No. 5,084,144, 1992.[4] E.J. Taylor, E.B. Anderson, N.R.K. Vilambi, Journal of The Electrochemical Society, 139 (1992) L45-L46.

Synthesis of a Nickel Single-Atom Catalyst Based on Ni–N4–xCx Active Sites for Highly Efficient CO2 Reduction Utilizing a Gas Diffusion Electrode

2020 ◽  
Vol 3 (9) ◽  
pp. 8739-8745
Author(s):  
Syed Asad Abbas ◽  
Jun Tae Song ◽  
Ying Chuan Tan ◽  
Ki Min Nam ◽  
Jihun Oh ◽  
...  
Keyword(s):  
Active Sites ◽  
Co2 Reduction ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode ◽  
Single Atom ◽  
Highly Efficient

scholarly journals CO2 Reduction to CO with 19% Efficiency in a Solar-Driven Gas Diffusion Electrode Flow Cell under Outdoor Solar Illumination

2020 ◽  
Vol 5 (2) ◽  
pp. 470-476 ◽  
Author(s):  
Wen-Hui Cheng ◽  
Matthias H. Richter ◽  
Ian Sullivan ◽  
David M. Larson ◽  
Chengxiang Xiang ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Flow Cell ◽  
Gas Diffusion ◽  
Gas Diffusion Electrode
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