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Electrochemical reduction of carbon dioxide to acetic acid on a Cu–Au modified boron-doped diamond electrode with a flow-cell system

MetadataDetails
Publication Date2023-01-01
JournalRSC Advances
AuthorsMillati H. Saprudin, Prastika Krisma Jiwanti, Deden Saprudin, Afiten R. Sanjaya, Yulia Mariana Tesa Ayudia Putri
InstitutionsUniversity of Indonesia, IPB University
Citations9
AnalysisFull AI Review Included

Technical Documentation & Analysis: Bimetal-Modified BDD for CO₂ Electroreduction

Section titled “Technical Documentation & Analysis: Bimetal-Modified BDD for CO₂ Electroreduction”

This document analyzes the research paper detailing the use of Cu-Au modified Boron-Doped Diamond (BDD) electrodes in a flow-cell system for the electrochemical reduction of carbon dioxide (eCO₂R) to formic acid and acetic acid. This analysis highlights the critical role of high-quality BDD substrates and directly connects the material requirements to 6CCVD’s advanced manufacturing capabilities.


  • High-Performance Electrocatalysis: Boron-Doped Diamond (BDD) electrodes, modified with bimetallic Copper-Gold (CuAu) particles, were successfully employed as highly stable working electrodes for eCO₂R.
  • Optimal Product Yield: The CuAu-BDD system achieved a maximum Faradaic Efficiency (FE) of 40.31% for Formic Acid (HCOOH) and 3.63% for Acetic Acid (CH₃COOH) at an applied potential of -1.0 V (vs. Ag/AgCl).
  • Flow System Advantage: Utilizing a flow-cell architecture accelerated the production rate of acetic acid and reduced the optimal CO₂ reduction potential from -1.5 V (required for Cu-BDD) to -1.0 V.
  • Enhanced Stability: The inclusion of Gold (Au) in the bimetallic modification significantly improved the stability of the deposited metal particles on the BDD surface compared to single-metal (Cu) modification, crucial for long-term flow-cell operation.
  • Material Requirement: The success of this research hinges on the availability of high-quality, highly conductive BDD substrates, a core offering of 6CCVD.

The following hard data points were extracted from the study detailing the optimal performance of the CuAu-BDD electrode in the flow-cell system.

ParameterValueUnitContext
Optimal Applied Potential-1.0V (vs. Ag/AgCl)For maximum HCOOH FE using CuAu-BDD
Optimal Electrolyte Flow Rate50mL min-1Maximized CO₂ mass transport
Max HCOOH Faradaic Efficiency40.31%Achieved using CuAu-BDD at -1.0 V
Max CH₃COOH Faradaic Efficiency3.63%Achieved using CuAu-BDD at -1.0 V
Max HCOOH Production Rate4.88mol m-2 s-1CuAu-BDD performance
Max CH₃COOH Production Rate0.11mol m-2 s-1CuAu-BDD performance
Reduction Potential Shift-1.5 to -1.0VReduction achieved by using CuAu-BDD in flow cell
Optimal Au Deposition (Weight%)1.48Weight%On CuAu-BDD surface (EDS analysis)
Optimal Cu Deposition (Weight%)0.12Weight%On CuAu-BDD surface (EDS analysis)

The experimental success relied on precise control over the BDD material synthesis and subsequent surface modification.

  1. BDD Synthesis: Boron-doped diamond films were prepared using Chemical Vapor Deposition (CVD), utilizing methane (CH₄) as the carbon source and trimethylboron (B(CH₃)₃) as the boron source in a hydrogen (H₂) atmosphere.
  2. Electrode Pre-treatment: BDD substrates underwent ultrasonication in isopropanol and ultrapure water, followed by electrochemical pre-treatment in 0.1 M H₂SO₄.
  3. Bimetallic Electrodeposition: Copper (Cu) and Gold (Au) particles were deposited simultaneously onto the BDD surface using a solution containing 1 mM CuSO₄ and 1 mM HAuCl₄.
  4. Deposition Potential: A reduction potential of -0.6 V (vs. Ag/AgCl) was applied to ensure the simultaneous reduction and deposition of both metal cations onto the BDD surface.
  5. Flow-Cell Operation: The electrochemical reduction was performed in a flow system using a three-electrode setup (CuAu-BDD working electrode, Pt counter electrode, Ag/AgCl reference electrode).
  6. Gas Management: The 0.5 M KCl electrolyte was aerated sequentially with N₂ (15 min) and CO₂ (15 min) to achieve optimal CO₂ dissolution, which was confirmed by linear sweep voltammetry (LSV).
  7. Product Quantification: Reaction products (HCOOH and CH₃COOH) were quantified using High-Performance Liquid Chromatography (HPLC) with a UV detector.

6CCVD is uniquely positioned to supply the foundational materials and advanced customization required to replicate, scale, and extend this high-efficiency eCO₂R research.

The core requirement of this research is a highly conductive, stable diamond substrate. 6CCVD provides the necessary material with superior control:

  • Heavy Boron-Doped Diamond (BDD) Wafers/Plates: We supply high-quality BDD material, essential for minimizing ohmic losses and maximizing the wide potential window required for selective CO₂ reduction over hydrogen evolution. Our BDD substrates are available in custom thicknesses (0.1 µm to 500 µm) and substrate sizes up to 10 mm thick.
  • Polycrystalline Diamond (PCD) Substrates: For large-scale flow-cell reactors, 6CCVD offers PCD plates up to 125 mm in diameter, providing the necessary surface area for industrial scale-up of this promising eCO₂R technology.

The paper utilized electrodeposition for surface modification. 6CCVD offers advanced, integrated metalization services that can provide superior uniformity and adhesion, enhancing long-term stability in flow systems.

Research Requirement6CCVD Customization SolutionTechnical Advantage
Bimetallic Layer (Cu/Au)Custom Metalization Services: We offer internal deposition of Au, Cu, Pt, Ti, Pd, and W using high-precision techniques (e.g., sputtering or e-beam evaporation).Ensures highly uniform, stable bimetallic nanoparticle layers with superior adhesion compared to simple wet electrodeposition, crucial for flow-cell longevity.
Electrode DimensionsCustom Dimensions & Laser Cutting: Supply of BDD plates in exact dimensions required for specific flow-cell geometries (e.g., microfluidic or large-area reactors).Facilitates seamless integration into existing or next-generation flow system designs, supporting rapid prototyping and scale-up.
Surface FinishUltra-Low Roughness Polishing: Polishing services achieving Ra < 1 nm (SCD) or Ra < 5 nm (PCD).A smoother BDD surface allows for more controlled and uniform nanoparticle deposition, potentially improving catalytic selectivity and stability.

The optimization of BDD for electrocatalysis requires deep material science expertise.

  • Electrocatalysis Optimization: 6CCVD’s in-house PhD team specializes in assisting researchers with material selection, optimizing boron doping levels, and controlling surface termination (e.g., hydrogen vs. oxygen termination) to maximize the Faradaic Efficiency and selectivity for similar electrochemical CO₂ reduction projects.
  • Global Logistics: We ensure reliable global shipping (DDU default, DDP available) of sensitive diamond materials, supporting international research collaborations.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Boron-doped diamond (BDD) was modified with copper and gold particles by using an electrodeposition technique to improve its catalytic effect on CO 2 reduction in a flow system.