Electrochemical Manufacturing Research Articles

(Invited) Achieving Robustness and Economic Viability in CO2 Electrolysis Scale-up: Key Results from RenewCO2

RenewCO2 is commercializing processes to convert carbon emissions from chemical manufacturing, which contributes 274 million metric tons of CO2eq annually in the U.S. alone. Our pioneering electrocatalytic Carbon Utilization Technology (eCUT) is adept at upcycling CO2 from hard-to-decarbonize industrial sources. By synthesizing commodity chemicals from CO2 emissions, eCUT promises high energy efficiency while producing carbon-negative materials. The critical innovation of RenewCO2’s eCUT process is deploying catalysts designed with readily available metals, optimizing the process to reduce CO2 into multi-carbon chemicals selectively with impressive energy efficiency.RenewCO2 has significantly advanced CO2 electrolyzer scale-up, focusing on demonstrating process robustness and economic feasibility. Targeting liquid products such as monomers (glycols), RenewCO2 has demonstrated cost-advantaged process economics compared to the incumbent petrochemical and bio-derived routes. We present detailed findings on the enhanced performance of our proprietary catalysts, which have shown remarkable endurance under prolonged operational conditions (1000 h of operation) in a scaled-up stack containing five 500 cm2 electrodes. The RenewCO2 team has demonstrated consistent electrolyzer performance with minimal degradation over extended periods. We also delve into improvements in energy efficiency, showcasing how these enhancements contribute to the overall process economics.The purification process is crucial in making carbon-negative materials from CO2 that do not require a green premium. In this regard, RenewCO2 has achieved remarkable progress in demonstrating a highly energy-efficient product purification. In collaboration with Argonne National Lab, we have developed an advanced electrochemical separation method that removes ionic species from the products to comply with strict industrial standards and increase their market value. A key development in this area is our innovative approach to electrodeionization, which combines ion-exchange membranes with electrically active media. This method exhibits low energy consumption, robustness, and simple operation. These advancements in the purification process are integral to our system’s overall efficiency and are pivotal in our pursuit of creating economically viable and sustainable electrochemical manufacturing solutions.On the economic front, we provide an in-depth analysis of the cost implications of scaling up. This includes a breakdown of the capital and operational costs, along with a comparative analysis with existing technologies. We discuss the main factors contributing to product cost and strategies to minimize them, such as the integration of low-cost materials and judicious choice of operating conditions.Our aim is to provide a transparent and comprehensive overview of the challenges and the state-of-the-art in scaling up CO2 electrolysis to liquid products, offering valuable insights for the scientific community and stakeholders in the field.

Versatile electrochemical manufacturing of mixed metal sulfide/N-doped rGO composites as bifunctional catalysts for high power rechargeable Zn–air batteries

Electrodeposition was used for direct synthesis of nitrogen-dopged reduced graphene oxide (NrGO) and mixed transition metal sulfides (NCMS). The resulting NCMS/NrGO composite exhibits excellent OER/ORR peroformance as Zn–air battery cathode.

Ammonia Recovery from Manure Wastewater and Simultaneous Electrosynthesis and Wastewater Treatment Using Ion Selective Redox Material

The environmental pressure due to greenhouse gas emissions and water contamination generated by livestock manure motivates the development of new approaches to reduce their environmental impacts and improve sustainability. Effective approaches to recover nutrients, especially ammonia, from manure wastewater to produce fertilizer are needed. Here we develop a new electrochemical strategy to achieve simultaneous ammonium (NH4 +) ion recovery and electrochemical synthesis using potassium nickel hexacyanoferrate as the ammonium ion-selective redox material to mediate the process. Our approach is built on our recent advances in designing modular electrochemical synthesis mediated using redox active materials (which we call redox reservoirs). Specifically, NH4 + (and K+) can be spontaneously uptaken from manure wastewater with a nutrient (NH4 + and K+) selectivity of ~100% driven by the oxidation of organic matter. Subsequently, NH4 +-rich fertilizers are released electrochemically together with the electrosynthesis of value-added chemicals, such as H2O2 as a disinfectant, without expensive ion-exchange membranes. We will also discuss our preliminary results on simultaneous advanced oxidation processes to improve the treatment of PFAS chemicals in wastewater. These results provide a new conceptual strategy for distributed electrochemical resource recovery and on-demand electrochemical manufacturing that can improve the sustainability of agricultural and wastewater treatment processes

Integrating Sustainable Design into Advanced Electrochemical Manufacturing

Considering the green engineering principles developed by Anastas and Zimmerman or detailed from the Sandestin conference of 2004 as presented by Abraham and Nguyen there is a duty of care as environmental stewards of our technology to closely examine where we can reduce impact regarding nascent electrochemical technologies.Comparison of state-of-the-art electrochemical manufacturing technologies highlight the design options competing technologies offer when we consider the sourcing, manufacturing, emissions, and other ways of embodying the environmental footprint of our designed processes.Impact on natural systems, circular life-cycle thinking and creating engineering solutions beyond our current or dominant manufacturing technologies to improve, innovate and invent solutions for a transition to a clean energy future are highlighted. Principles of conservation and improvement of natural ecosystems are considered to inform novice scientists and engineers and lead to insight in opportunities for advanced system developments for mature industry representatives and experienced experts.Challenges in greening of existing systems offers opportunities for continued growth in the industrial domain. Triple bottom line examination of how our actions can improve manufacturing processes, as well as benefit globally relevant sustainable development goals. Reframing the basis for how we design electrochemical processes from a cost-efficiency relationship to include additional considerations in our practice using simple guidelines to address cell architectures, integration and interconnection of energy and material flows, and careful material selection are shown to have a win-win benefit when we examine intergenerational scope of our practice.

Ammonium Recovery from Manure Wastewater and Simultaneous Electrosynthesis Using Ammonium-Ion Selective Redox Material

The environmental pressure due to greenhouse gas emissions and water contamination generated by livestock manure motivates the development of new approaches to reduce their environmental impacts and improve sustainability. Effective approaches to recover nutrients, especially ammonium, from manure wastewater to produce fertilizer are needed. Here we develop a new electrochemical strategy to achieve simultaneous ammonium recovery and electrochemical synthesis using potassium nickel hexacyanoferrate (KNiHCF) as the ammonium ion-selective redox material to mediate the processes. The KNiHCF electrode spontaneously uptakes ammonium (and K+) from manure wastewater with a nutrient (NH4 + and K+) selectivity of ~100% and effective reduction of chemical oxygen demand (COD). The subsequent electrochemical process achieves the co-production of NH4 +-rich fertilizers and value-added chemicals, such as H2 as a green fuel and H2O2 as a disinfectant, without expensive ion-exchange membranes. These results provide a new conceptual strategy and insights for distributed electrochemical resource recovery and on-demand electrochemical manufacturing that can improve agricultural sustainability.

Current and Emerging Electrochemical Approaches for Chemical Manufacturing

R&D on electrochemical approaches for chemical manufacturing is experiencing a renaissance, the direct result of society’s desire to reduce greenhouse gas emissions of the chemical industry, aiming to be carbon neutral by 2050. Two such processes have been performed for decades at scale: the chlor-alkali process that produces chlorine from aqueous sodium chloride, and the production of adiponitrile, an intermediate in the production nylon-6,6. Water electrolysis for hydrogen production is also being deployed now at scale. This report summarizes some of the many efforts to electrify chemical conversions, often using renewable feeds like water, CO2, and biomass-derived adducts, or waste-streams from other processes. Beyond efforts to reduce emissions, a very active research community also pursues a broad range of electro-organic conversions, some of which have major advantages over conventional reaction chemistries. Overarching challenges of implementing electrochemical manufacturing approaches are also discussed (e.g., limited familiarity with electrochemical processes in chemical engineering practice, insufficient availability of electrical power, and the variability of various renewable feeds).

Analysis of influence of process parameters in ultrasonic assisted jet electrochemical manufacturing

Analysis of influence of process parameters in ultrasonic assisted jet electrochemical manufacturing

Evaluating the Application of Artificial Intelligence in Electrochemical Manufacturing: A Comprehensive Analysis

Electrochemical machining (ECM) is a critical manufacturing process used to produce complex and difficult-to-machine materials with high precision and accuracy. The process involves the removal of material through a controlled electrochemical reaction between an electrolyte and an electrically conductive workpiece. With the increasing demand for high-quality products and the need to improve manufacturing efficiency, the use of artificial intelligence (AI) in ECM is becoming increasingly important. AI algorithms can be used to optimize process parameters, detect defects and anomalies, predict maintenance requirements, and optimize the design of workpieces and tooling. This paper provides an overview of the role of AI in ECM, including recent developments, applications, and future prospects.

Electrochemical Manufacturing Routes for Organic Chemical Commodities.

Electrochemical synthesis of organic chemical commodities provides an alternative to conventional thermochemical manufacturing and enables the direct use of renewable electricity to reduce greenhouse gas emissions from the chemical industry. We discuss electrochemical synthesis approaches that use abundant carbon feedstocks for the production of the largest petrochemical precursors and basic organic chemical products: light olefins, olefin oxidation derivatives, aromatics, and methanol. First, we identify feasible routes for the electrochemical production of each commodity while considering the reaction thermodynamics, available feedstocks, and competing thermochemical processes. Next, we summarize successful catalysis and reaction engineering approaches to overcome technological challenges that prevent electrochemical routes from operating at high production rates, selectivity, stability, and energy conversion efficiency. Finally, we provide an outlook on the strategies that must be implemented to achieve large-scale electrochemical manufacturing of major organic chemical commodities.

New Developments in Electrochemical Manufacturing

New Developments in Electrochemical Manufacturing

A systematic review on high speed selective jet electrodeposition manufacturing

PurposeThe purpose of this paper is to present current state of understanding on jet electrodeposition manufacturing; to compare various experimental parameters and their implication on as deposited features; and to understand the characteristics of jet electrodeposition deposition defects and its preventive procedures through available research articles.Design/methodology/approachA systematic review has been done based on available research articles focused on jet electrodeposition and its characteristics. The review begins with a brief introduction to micro-electrodeposition and high-speed selective jet electrodeposition (HSSJED). The research and developments on how jet electrochemical manufacturing are clustered with conventional micro-electrodeposition and their developments. Furthermore, this study converges on comparative analysis on HSSJED and recent research trends in high-speed jet electrodeposition of metals, their alloys and composites and presents potential perspectives for the future research direction in the final section.FindingsEdge defect, optimum nozzle height and controlled deposition remain major challenges in electrochemical manufacturing. On-situ deposition can be used as initial structural material for micro and nanoelectronic devices. Integration of ultrasonic, laser and acoustic source to jet electrochemical manufacturing are current trends that are promising enhanced homogeneity, controlled density and porosity with high precision manufacturing.Originality/valueThis paper discusses the key issue associated to high-speed jet electrodeposition process. Emphasis has been given to various electrochemical parameters and their effect on deposition. Pros and cons of variations in electrochemical parameters have been studied by comparing the available reports on experimental investigations. Defects and their preventive measures have also been discussed. This review presented a summary of past achievements and recent advancements in the field of jet electrochemical manufacturing.

(Corrosion Division H. H. Uhlig Award) The Journey from Numerical Simulations to Impedance Analysis

Our work in corrosion has encompassed numerical simulations and electrochemical impedance spectroscopy. This presentation provides an overview of insights gained from these endeavors.Numerical simulations train insightIn collaboration with Kevin Kennelley and Lee Bone, then from Arco, our group developed boundary-element models to simulate cathodic protection (CP) of pipelines with coating defects that exposed bare steel. Designed initially for the trans-Alaska pipeline,1 the model was extended to account for multiple pipes, multiple CP systems,2 buried tanks, and tank bottoms.3 The program could be used to simulate rectifier wars in which impressed current on one CP system can induce corrosion on adjacent or crossing systems. This program was used to demonstrate the behavior of heterogeneous anodes. For example, addition of impressed current anodes to an inadequate set of sacrificial anodes runs the risk of protecting the sacrificial anodes at the expense of protecting steel exposed by coating defects.In collaboration with Richard Woollam, then with BP, and, later, with Scott Briggs, NWMO, our group developed finite-element COMSOL models that accounted for corrosion under droplets containing dissolved oxygen.4 The models include coupled, nonlinear, conservation equations for ionic species, which account for migration, diffusion, local electroneutrality, homogeneous reactions, and formation of precipitates. The presence of anodic and cathodic regions was not assumed a priori, but was rather the result of numerical simulations, which revealed galvanic coupling caused by differential aeration cells. This work showed that, while differential aeration created nonuniform corrosion for steel covered by a deposit or droplet, corrosion of copper was largely uniform.Impedance spectroscopy can provide useful parametersWhile the use of the Stern-Geary relationship to extract corrosion current is well known, this approach applies only for systems under kinetic control. More information may be extracted from the ubiquitous constant-phase-element (CPE) behavior. In collaboration with scientists/engineers from France and Italy, our group developed the power-law model, which provides an equation that relates CPE parameters to film thickness, dielectric constant, and film resistivity at the film-electrolyte interface.5,6 This model can be augmented with the measurement model, from which capacitance may be extracted.7 Thus, if the dielectric constant is known, the measurement model can yield the corresponding film thickness and the power-law model can yield the resistivity distribution in the film.8 An early version of this approach is now in commercial use.9 Acknowledgements I am grateful for all the students and collaborators who walked part of this journey with me. These include students J. Matthew Esteban and Doug Riemer (CP models), Ya-Chiao Chang and Chen You, (droplet models), and Bryan Hirschorn (power-law model). I thank collaborators Bernard Tribollet, Vincent Vivier, Marco Musiani, and Nadine Pébère, with whom I have explored the arcane arts of impedance spectroscopy. Finally, I thank the Corrosion Division awards committee for bestowing upon me the 2022 H. H. Uhlig Award. References E. Orazem, J. M. Esteban, K. J. Kennelley, and R. M. Degerstedt, “Mathematical Models for Cathodic Protection of an Underground Pipeline with Coating Holidays: 1. Theoretical Development,” Corrosion, 53 (1997), 264-272.Liu, A. Shankar, M. E. Orazem, and D. P. Riemer, “Numerical Simulations for Cathodic Protection of Pipelines,” in Underground Pipeline Corrosion: Detection, Analysis, and Prevention, M. E. Orazem, editor, Woodhead Publishing Limited, Cambridge, UK, 2014, 85-126.P. Riemer and M. E. Orazem, “A Mathematical Model for the Cathodic Protection of Tank Bottoms,” Corrosion Science, 47 (2005), 849-868.-C. Chang, R. Woollam, and M. E. Orazem, “Mathematical Models for Under-Deposit Corrosion: 1. Aerated Media,” Journal of The Electrochemical Society, 161 (2014), C321-C329.Hirschorn, M. E. Orazem, B. Tribollet, V. Vivier, I. Frateur, and M. Musiani, “Constant-Phase-Element Behavior Caused by Resistivity Distributions in Films: 1. Theory,” Journal of The Electrochemical Society, 157 (2010) C452-C457.E. Orazem, B. Tribollet, V. Vivier, S. Marcelin, N. Pébère, A. L. Bunge, E. A. White, D. P. Riemer, I. Frateur, and M. Musiani, “Dielectric Properties of Materials showing Constant-Phase Element (CPE) Impedance Response,” Journal of The Electrochemical Society, 160 (2013), C215-C225.Liao, W. Watson, A. Dizon, B. Tribollet, V. Vivier, and M. E. Orazem, “Physical Properties Obtained from Measurement Model Analysis of Impedance Measurements,” Electrochimica Acta, 354 (2020), 136747.You, A. Titov, B. H. Kim, and M. E. Orazem, “Impedance Measurements on QLED Devices: Analysis of High-Frequency Loop in Terms of Material Properties,” Journal of Solid-State Electrochemistry, 24 (2020), 3083-3090.P. Riemer and M. E. Orazem, “Impedance-Based Characterization of Raw Materials as Used in Electrochemical Manufacturing,” The Electrochemical Society Interface, Fall 2014, 23:3 (2014), 63-67.

Challenges in Electrifying Chemical Manufacturing

Current processes used for the conversion of fossil fuel feedstock to fuels and other chemicals or intermediates as well as those used in chemical manufacturing in general tend to be highly carbon positive. These industries indeed are significant contributors to emission of excess carbon dioxide. Often this is the result of the use of fossil-fuel driven processes to yield the high temperatures and/or pressures needed to drive these processes, even in the presence of catalysts. Already, options to replace these energy-intense, carbon positive processes with less carbon positive processes is underway, for example the use of electricity driven processes.This presentation will explore the status of electrolytic processes for chemical conversion at scale. Significant progress has been made in the electrochemical manufacturing of intermediates of key importance to the chemical industry (e.g., H2, CO, ethylene, ethanol, acetate, ...) using renewable feedstocks such as water and CO2. While electrocatalysts with reasonable activity and selectivity for these intermediates have been developed or are still being developed, several challenges still remain in the desired translation of these electrocatalytic conversion approaches to scalable electrochemical processes. This presentation will review issues and progress regarding a number aspects: (1) electrode durability, how to mitigate electrode degradation processes; (2) scalability of electrolysis cell designs; (3) opportunities for co-conversion, producing value-added products at both electrodes; (4) techno-economic and life cycle assessment of new electrochemical approaches to chemical manufacturing. Furthermore, the presentation will elaborate on associated challenges and needs, such as (i) the variability in composition of many renewable feedstocks (e.g., CO2 from different industrial plants, bio-derived substrates); and (ii) the need for new separations approaches, ideally renewable energy driven, able to purify the new/different product streams from the electrolytic chemical manufacturing processes.

Elucidating Pathways to Electrochemical Reduction of Furfural Via Tailoring Interfacial Environments Toward Selective Production of Valuable Furanic Chemicals

Electrochemical reduction of biomass-derived feedstocks holds great promise to produce value-added chemicals or fuels driven by renewable electricity. However, mechanistic understanding of the aldehyde reduction toward valuable products at the electrode/electrolyte interface at the molecular level is still lacking. Herein, we studied the furfural reduction on Pb electrodes in acid conditions and elucidated the detailed pathways toward three key products: furfuryl alcohol (FA), 2-methylfuran (MF), and hydrofuroin. First, by coupling isotopic labeling and electrokinetics, we revealed that protons (H2O and H3O+) plays an important role in the hydrogenation pathway toward FA and MF. In particular, the study of product-selective kinetic isotopic effect of H/D and the surface property-dependent hydrogenation/deuteration pathway strongly impacted the generation of FA but not MF, which can be attributed to their different formation mechanisms: FA is produced from Langmuir-Hinshelwood pathway that need both adsorbed furfural and hydrogen, but MF produced from Eley-Rideal pathway that need proton directly from the electrolyte. Modifying the double layer by cations with large radii, we further correlated the product selectivity (FA and MF) with interfacial environments (local H3O+ and H2O content, etc). Combined methods, including pulsed electrolysis, electron paramagnetic resonance (EPR) spectroscopy, and DFT calculations, further suggested that the formation of hydrofuroin and FA shared one intermediate. Hydrofuroin is produced through the desorption of the intermediate as ketyl radicals followed by its self-coupling in the electrolyte, while FA is generated from further hydrogenation of that intermediate. The acquired into the electrochemical reduction of the aldehyde group in furfural to alcohol, alkyl, and dimer may be extended to other organic compounds with carbonyl group, such as 5-hydromethylfurfural, toward a sustainable electrochemical manufacturing of higher-valued chemicals from biomass feedstock.

Emerging Electrochemical Processes to Decarbonize the Chemical Industry.

Electrification is a potential approach to decarbonizing the chemical industry. Electrochemical processes, when they are powered by renewable electricity, have lower carbon footprints in comparison to conventional thermochemical routes. In this Perspective, we discuss the potential electrochemical routes for chemical production and provide our views on how electrochemical processes can be matured in academic research laboratories for future industrial applications. We first analyze the CO2 emission in the manufacturing industry and conduct a survey of state of the art electrosynthesis methods in the three most emission-intensive areas: petrochemical production, nitrogen compound production, and metal smelting. Then, we identify the technical bottlenecks in electrifying chemical productions from both chemistry and engineering perspectives and propose potential strategies to tackle these issues. Finally, we provide our views on how electrochemical manufacturing can reduce carbon emissions in the chemical industry with the hope to inspire more research efforts in electrifying chemical manufacturing.

Microbial | electrochemical CO2 reduction: To integrate or not to integrate?

Microbial | electrochemical CO2 reduction: To integrate or not to integrate?

Versatile, low-cost, non-toxic potentiometric pH-sensors based on niobium

A low-cost potentiometric pH electrode based on niobium/niobium oxide was developed with excellent stability over several months under various storage conditions. Three fast and simple preparation routes including thermal growth as well as chemical and electrochemical deposition were tested. Our data demonstrates that the electrochemical manufacturing method produces pH electrodes with high reproducibility and a sensitivity of −41 mV/pH. OCP (Open Circuit Potential) measurements showed that the pH electrode can be used over a wide pH range from pH 2 to 12. Furthermore, the oxide layer of all produced electrodes was characterized and compared via SEM (Scanning Electron Microscopy), EDX (Energy-Dispersive X-Ray Spectroscopy) and EIS (Electrochemical Impedance Spectroscopy). It was shown that the electrochemical fabrication route leads to the highest porosity, which is in turn linked to the highest sensitivity. The hysteresis of this pH sensor was determined to be 2 mV in a pH region between 4 and 10. In long-term experiments a drift of 1.1 mV/h was obtained. Negligible interference was observed with NaCl and KCl ions, whereas sensitivity and linearity were affected by Li-ions.

Renewable Electricity Enables Green Routes to Fine Chemicals and Pharmaceuticals.

Syntheses of chemicals using renewable electricity and when generating high atom economies are considered green and sustainable processes. In the present state of affairs, electrochemical manufacturing of fine chemicals and pharmaceuticals is not as common place as it could be and therefore, merits more attention. There is also a need to turn attention toward the electrochemical synthesis of valuable chemicals from recyclable greenhouse gases that can accelerate the process of circular economy. CO2 emissions are the major contributor to human-induced global warming. CO2 conversion into chemicals is a valuable application of its utilisation and will contribute to circular economy while maintaining environmental sustainability. Herein, we present an overview of electro-carboxylation, including mechanistic aspects, which forms carboxylic acids using molecular carbon dioxide. We also discuss atom economies of electrochemical fluorination, methoxylation and amide formation reactions.

Sustainable Coproduction of Two Disinfectants via Hydroxide-Balanced Modular Electrochemical Synthesis Using a Redox Reservoir.

Challenges posed by the sacrificial auxiliary reactions and expensive ion-exchange membranes in conventional electrosynthesis necessitate developing new electrochemical processes to enable efficient and sustainable distributed electrochemical manufacturing. Modular electrochemical synthesis (ModES) using a redox reservoir (RR) offers a promising membrane-free approach to improve energy efficiency and reduce waste through the pairing of multiple independent oxidative and reductive half-reactions; however, undesired ion-imbalance and induced pH changes in the existing ModES process limit sustained production. Here we present Ni(OH)2 as a heterogeneous RR that can selectively store and transport the hydroxide ions involved in the target half-reactions by reversible conversion with NiOOH to enable an ion-balanced ModES of two common disinfectants, hydrogen peroxide (H2O2) and sodium hypochlorite (NaClO). This hydroxide-balanced ModES realizes stable operation without appreciable pH swing to accumulate practically useful concentrations of H2O2 and NaClO up to 251 and 481 ppm, respectively. These results illustrate additional design principles for electrosynthesis without sacrificial auxiliary reactions and the need for ion-selective RRs for modular electrochemical manufacturing.

Enabling Green Chemicals via Electrochemical Manufacturing

As renewable energy like wind or solar has become widespread globally, many essential industrial chemicals , which are conventionally produced using chemical approaches, can be manufactured in an electrochemical way. This electrochemical manufacturing, when integrated with low-cost renewable energy, provides a green or sustainable approach to producing chemicals with significantly reduced or completely eliminated carbon footprints.In this work, we will focus on the electrochemical manufacturing of green hydrogen (H2), ammonia (NH3) and ethylene (C2H2). Major components including electrocatalysts and ion exchange membranes for these chemicals will be discussed in detail. We will also present current challenges that can include low efficiency, poor durability, and high cost of the electrochemical reactors. Particularly, we will compare electrochemical manufacturing with conventional chemical production, from a techno-economical point of view. Finally, we will point out to existing great opportunities of electrochemical manufacturing.The implementation of electrochemical manufacturing can address grid intermittency by smartly utilizing off-peak renewable electricity, reduce chemical transport by making distributed plants, and improve process efficiency by coupling electrochemical synthesis-separation.