Electrochemical Membrane Reactor Research Articles

Hexagonal boron nitride-doped carbon membrane as anode for the enhanced adsorption and electrochemical oxidation of phenol

An activated carbon membrane (ACM) doped with hexagonal boron nitride (h-BN) was fabricated by using activated carbon as the raw material and phenolic resin as the binder. The preparation process involves blending raw materials, ball milling, membrane pressing, and high-temperature carbonization. The conductive ACM was employed as an anode to constitute an electrochemical membrane reactor (EMR) for phenol removal. The effect of h-BN doping rate (0–5wt.%) on the properties of ACM was explored. Results showed that ACM1 (1wt.% h-BN) displayed a small pore size (20nm), high porosity (41.6%), large specific surface area (446.8 m2/g), and strong mechanical strength (15.4MPa) compared to the pristine ACM0. The oxygen precipitation potential of ACM1 (2.11V) was much higher than that of ACM0 (1.53V), thus reducing oxygen generation at the anode in EMR for phenol degradation. The phenol removal rate of phenol obtained from EMR with ACM1 as the anode at 1.5V was up to 95.6%, which was much higher than that for ACM0 (39.3%). Density functional theory (DFT) calculations and experimental results confirmed that h-BN-doping enhanced the adsorption active sites, and adsorption energy, leading to the high performance of EMR for phenol removal. In addition, the equilibrium adsorption capacity of ACM1 (10.2mg/g) was much higher than that of ACM0 (3.7mg/g). The C atoms adjacent to pyridine N in ACM1 were identified as the adsorption and active catalytic sites by X-ray photoelectron spectroscopy (XPS) and DFT calculations. Therefore, this study sheds light on the design and fabrication of conductive carbon membranes for enhanced performance in industrial wastewater treatment.

Graphene Oxide Membrane Reactor for Electrochemical Deuteration Reactions.

The deuteration of organic molecules is considerably important in organic and medicinal chemistry. An electrochemical membrane reactor using proton-conducting graphene oxide (GO) nanosheets was developed to synthesize valuable deuterium-labeled products via an efficient hydrogen-to-deuterium (H/D) exchange under mild conditions at ambient temperature and atmospheric pressure. Deuterons (D+) formed by the anodic oxidation of heavy water (D2O) at the Pt/C anode permeate through the GO membrane to the Pt/C cathode, where organic molecules with functional groups (C≡C and C═O) are deuterated with adsorbed atomic D species. Deuteration occurs in outstanding yields with high levels of D incorporation. We also achieved the electrodeuteration of a drug molecule, ibuprofen, demonstrating the promising feasibility of the GO membrane reactor in the pharmaceutical industry.

Combined carbon capture and catalytic oxidative dehydrogenation of propane to propylene conversion through a plug-flow dual-phase membrane reactor

Combined carbon capture and conversion (3C) technologies play a vital role in our battle against global warming and climate. Using electrochemical cells for 3C is an attractive option due to their intrinsically high efficiency and selectivity. Here we report an electrochemical membrane reactor for CO2/O2 capture from flue gas and instant conversion of propane to propylene over a catalyst bed. The membrane consists of a dual metal-carbonate phase, which allows CO2/O2 (in 2:1 mol ratio) co-transport through the membrane. The reactor is in tubular plug-flow geometry, which enables a continuous and gradual addition of CO2/O2 into a flowing propane stream along the axial length of the membrane, thus achieving an excellent balance between conversion and selectivity, while avoiding overoxidation and suppressing coking. The plug-flow membrane reactor exhibits a C3H6 yield of ∼30 %, C3H8 conversion of ∼35 % and C3H6 selectivity of 85 % at 600 °C for an impressive 173 h of continuous operation with minimal degradation.

Production of Novel Tubular Electrochemical Hydrogen Compressor

For most applications, especially transport, hydrogen needs to be compressed due to its low volumetric density. Conventionally, mechanical compressors are used for hydrogen compression, but they possess disadvantages such as high maintenance due to moving parts and a limited one-stage compression ratio. A promising technology to overcome those obstacles is electrochemical hydrogen compression, in which hydrogen is compressed in an electrochemical membrane reactor.To date, only planar electrochemical reactors for hydrogen compression have been investigated although tubular designs offer advantages in membrane area to reactor volume ratio, sealing options, pressure stability and reactor complexity. However, high contact and membrane resistances and scalable manufacturing processes are still challenges to be addressed for the advent of tubular electrochemical compressors in application.Herein we introduce a manufacturing process for tubular electrochemical hydrogen compression reactors. The developed cell comprises a catalyst coated porous tubular anode covered by a tubular proton exchange membrane, which was subsequently coated with the cathode catalyst layer. The porous anode was prepared via metal 3D printing. 3D printing enables tailored porosity and geometry by which mass transport is enhanced. The catalyst layer was applied by manual spray coating. Constant current experiments and electrochemical impedance spectroscopy were performed to characterize the as prepared tubular electrochemical compressor. The results revealed the importance of tailored contacting concepts and the optimization of components regarding water transport, as the efficiency of the process is dominated by contact and membrane resistances.

An insight into underlying purification mechanism of tannery wastewater based on carbon/sulfur segmented tracing strategy in electrochemical membrane reactor

Relying on co-precipitation and thermally induced phase separation methods, a novel triple-layered heterojunction catalytic electrode membrane (PVDF/La/Sm/CeO2, LMOHCEM) was developed and applied in coupled microbial fuel cell and membrane bioreactor (CMMS), achieving enhanced performance for treating tannery wastewater. Hydrophobic LMOHCEM exhibits increased electrochemical activity (qT* 3.53 × 10-3C cm−2, qo* 2.2 × 10-3C cm−2), indicating superior electron transfer efficiency. The oxygen reduction reaction (ORR) process mediated by LMOHC follows a 2 × 2 e- transfer pathway, and density functional theory (DFT) calculations demonstrates a negative Bader charge (-60 |e|) for the synthesized catalyst. To serve for engineering, the CMMS was implemented in the operation of continuous-flow for tannery wastewater treatment, the system achieved optimized pollutant removal property (COD 98.3%, Cr 99.1%, Sulfide and Sulfate 100%). Based on the segmented tracing strategy, the whole process of carbon/sulfur production of the electrochemical membrane reactor was analyzed. Microbial community analysis confirmed the dominant functional bacteria in the reactor. Elucidated multiple removal pathways and underlying purification mechanisms related to chromium and organic matter in the CMMS were proposed. Overall, this work provides a perspective for exploring an electrochemical membrane reactor with enhanced removal features for efficient electroplating wastewater treatment through typical element tracing analysis.

Flow-Through Electrochemical Membrane Reactor with a Self-Supported Carbon Membrane Electrode for Highly Efficient Synthesis of Hydrogen Peroxide.

In situ electroreduction of O2 to H2O2 by using electrons as reagents is known as a green process, which is highly desirable for environmental remediation and chemical industries. However, the development of a cost-effective electrode with superior H2O2 synthesis rate and stability is challenging. A self-supported carbon membrane (CM) was prepared in this study from activated carbon and phenolic resin by carbonization under a H2 atmosphere. It was employed as the cathode to build a flow-through electrochemical membrane reactor (FT-ECMR) for electrosynthesis of H2O2. The results showed that the CM had a small pore size (34 nm), a high porosity (42.3%), and a high surface area (450.7 m2 g-1). In contrast to most of the state-of-the-art self-supported carbon electrode reported in the previous works, the FT-ECMR exhibited a high concentration of continuous and stable H2O2 electrosynthesis (1042 mg L-1) as well as a H2O2 synthesis rate of 5.21 mg h-1 cm-2. It had also demonstrated a high oxygen conversion (0.37%) and current efficiency (88%). The outstanding performance of the FT-ECMR for H2O2 synthesis was attributed to the enhanced mass transfer of the reactor, the existence of a relatively high surface area of CM, and the abundant disordered carbon structures (sp3-C, defects, and edges). In conclusion, our work highlighted using the FT-ECMR with the CM to synthesize H2O2 efficiently and cost-effectively.

Endergonic Hydrogenation at Ambient Conditions Using an Electrochemical Membrane Reactor.

Here, we determine how the hydrogen loading (x) of an electrochemical palladium membrane reactor (ePMR) varies with electrochemical conditions (e.g., applied current density, electrolyte concentration). We detail how x influences the thermodynamic driving force of an ePMR. These studies are accomplished by measuring the fugacity (P) of hydrogen desorbing from the palladium-hydrogen membrane and subsequently relating P to pressure-composition isotherms to determine x. We find that x increases with both applied current density and electrolyte concentration, but plateaus at a loading of x ≅ 0.92 in 1.0 M H2SO4 at -200 mA·cm-2. The validity of the fugacity measurements is supported experimentally and computationally by: (a) electrochemical hydrogen permeation studies; and (b) a palladium-hydrogen porous flow finite element analysis (FEA) model. Both (a) and (b) agree with the fugacity measurements on the following x-dependent properties of the palladium-hydrogen system during electrolysis: (i) the onset for spontaneous hydrogen desorption; (ii) the point of steady-state hydrogen loading; and (iii) the function describing hydrogen desorption between (i) and (ii). We proceed to detail how x defines the free energy of palladium-hydrogen alloy formation (ΔG(x)PdH), which is a descriptor for the thermodynamic driving force of hydrogenation at the PdHx surface of an ePMR. A maximum value ΔGPdH of 11 kJ·mol-1 is observed, suggesting that an ePMR is capable of driving endergonic hydrogenation reactions. We empirically demonstrate this capability by reducing carbon dioxide to formate (ΔGCO2/HCO2H = 3.4 kJ·mol-1) at ambient conditions and neutral pH.

A high-efficiency electrochemical proton-conducting membrane reactor for ammonia production at intermediate temperatures

•Efficient electrochemical nitrogen reduction is successfully achieved at 350°C •The NH3 production and H2 purification processes are coupled in one reactor •The in situ supplied protons greatly accelerate the NH3 production rate Ammonia is a ubiquitous chemical raw material and hydrogen carrier with a wide range of industrial applications, which is mainly derived from the energy-intensive Haber-Bosch process. Herein, a high-efficiency ammonia synthesis technology through an excellent CO2-tolerant La5.5WO11.25 − δ (LWO) membrane reactor has been developed to improve electrocatalytic nitrogen reduction reaction performance by coupling with hydrogen purification at intermediate temperatures. From molecular hydrogen, the produced protons can be supplied in situ for ammonia synthesis by nitrogen hydrogenation. As a result, the superior ammonia synthesis performance with the highest Faradaic efficiency (FE) of 43.8% and corresponding ammonia rate of 231.1 μg h−1 cm−2 is achieved at 2,500 μA cm−2 at 350°C. This promising electrochemical membrane reactor for ammonia production at intermediate temperatures provides a feasible direction to promote the development of the ammonia synthesis industry. Ammonia is a ubiquitous chemical raw material and hydrogen carrier with a wide range of industrial applications, which is mainly derived from the energy-intensive Haber-Bosch process. Herein, a high-efficiency ammonia synthesis technology through an excellent CO2-tolerant La5.5WO11.25 − δ (LWO) membrane reactor has been developed to improve electrocatalytic nitrogen reduction reaction performance by coupling with hydrogen purification at intermediate temperatures. From molecular hydrogen, the produced protons can be supplied in situ for ammonia synthesis by nitrogen hydrogenation. As a result, the superior ammonia synthesis performance with the highest Faradaic efficiency (FE) of 43.8% and corresponding ammonia rate of 231.1 μg h−1 cm−2 is achieved at 2,500 μA cm−2 at 350°C. This promising electrochemical membrane reactor for ammonia production at intermediate temperatures provides a feasible direction to promote the development of the ammonia synthesis industry.

Electrification and decarbonization of spent Li-ion batteries purification by using an electrochemical membrane reactor

The expanding electric vehicle market brings with it exponential growth in the use of lithium (Li)-ion batteries (LIB) for which a wave of spent LIB is expected to come within the next 5 to 10 years. Due to the economic and strategic value imbedded within the metals contained in LIB, different recycling technologies, including hydrometallurgy, pyrometallurgy and direct recycling, are under development. Being different from previous hydrometallurgical methods, which may have high chemical consumption and negative environmental impact, an electrochemical membrane reactor is designed and validated for the first time, to electrify and decarbonize the impurity removal process. This reactor electroplates copper (Cu) and electrochemically precipitates aluminum (Al) and iron (Fe) from simulated spent LIB leachates, by consuming only air, water, and electricity, and the impurities are reduced to <1 ppm. The purified leachate maintains 99.5 % of the nickel (Ni), 95.4 % of the cobalt (Co) and 99.14 % of manganese (Mn) from the original leachate solution, and then can be directly applied for cathode precursor synthesis. Additionally, the purification process doesn’t introduce extra impurity, and the reactor restoration process generates valuable by-product hydro sulfate (H2SO4). This electrochemical process can reduce the cost, because of the much less chemical consumption and the valuable by-product generation, and mitigates the waste emissions, because of no extra impurity introduced and no greenhouse gas (GHG) produced. The chemical precipitation method uses significant amount of NaOH, which induced GHG emission during the manufacturing process.

Simultaneous generation of electricity, ethylene and decomposition of nitrous oxide via protonic ceramic fuel cell membrane reactor

Ethylene, one of the most widely produced building blocks in the petrochemical industry, has received intense attention. Ethylene production, using electrochemical hydrogen pump-facilitated nonoxidative dehydrogenation of ethane (NDE) to ethylene, is an emerging and promising route, promoting the transformation of the ethylene industry from energy-intensive steam cracking process to new electrochemical membrane reactor technology. In this work, the NDE reaction is incorporated into a BaZr0.1Ce0.7Y0.1Yb0.1O3−δ electrolyte-supported protonic ceramic fuel cell membrane reactor to co-generate electricity and ethylene, utilizing the Nb and Cu doped perovskite oxide Pr0.6Sr0.4Fe0.8Nb0.1Cu0.1O3−δ (PSFNCu) as anode catalytic layer. Due to the doping of Nb and Cu, PSFNCu was endowed with high reduction tolerance and rich oxygen vacancies, showing excellent NDE catalytic performance. The maximum power density of the assembled reactor reaches 200 mW cm−2 at 750 °C, with high ethane conversion (44.9%) and ethylene selectivity (92.7%). Moreover, the nitrous oxide decomposition was first coupled in the protonic ceramic fuel cell membrane reactor to consume the permeated protons. As a result, the generation of electricity, ethylene and decomposition of nitrous oxide can be simultaneously obtained by a single reactor. Specifically, the maximum power density of the cell reaches 208 mW cm−2 at 750 °C, with high ethane conversion (45.2%), ethylene selectivity (92.5%), and nitrous oxide conversion (19.0%). This multi-win technology is promising for not only the production of chemicals and energy but also greenhouse gas reduction.

Co-Generation of Hydrogen and Propylene Via Proton Conducting Fuel Cell Under Intermediate Temperature

Propylene and hydrogen are the two primary products of the proposed process. Propylene is an important raw material for polymer synthesis and chemical manufacture, while hydrogen is widely used in refining petroleum, treating metals, producing fertilizer, and processing foods. At present, the dominant technology for producing propylene is steam cracking, which is highly energy intensive and low energy efficiency due to side reactions and severe coke formation. This work demonstrates an electrochemical process which is achieved through a deprotonation reaction at the catalyst-assisted anode of an electrochemical membrane reactor (EMR) to co-produce propylene and hydrogen, using a highly active 3D ultra-porous nickel-free deficient layered perovskite anode, BaZrCe (BZC) electrolyte and Ni-cermet cathode. The electrochemical propane dehydrogenation reaction (PDR) performance was evaluated and optimized by varying reaction parameters, including current density, voltage, propane concentration, and temperature. Preliminary thermal catalytic measurements in a fixed bed flow reactor using a dilute (10%) propane gas as the feedstock. The results showed that propane conversion could reach up to 40% at 550°C. By reducing operation temperature to 350-500°C, the technology also improves the durability of the catalyst and the electrochemical system. Therefore, the proposed technology represents an innovative and significant improvement with respect to existing commercial processes.

Evaluation of an electrochemical membrane reactor for the removal of β-blocker compound from water

As part of the Brazilian Popular Pharmacy Program, the β-blocker Atenolol (ATN) is widely used, and its presence in the environmental ecosystems is a reality. Aiming the ATN removal, the use of an electrochemical membrane reactor was evaluated and compared to a membraneless one. The results show that the generation of SO4•− in the membrane reactor occurs by the reaction of HSO4−/H2SO4 scavenging HO•, whereas, in the membraneless reactor, the SO4•− generation occurs mainly by the direct oxidation mechanism. Operating both reactors in the same hydrodynamic conditions, it was found that the concentrations of SO4•− and S2O82− are higher in the membrane reactor, leading to a greater concentration of these species being transported to the bulk solution, changing the kinetics, and presenting better results in electrochemical combustion (ϕ), mineralization current efficiency (MCE) and specific energy consumption (Es). Since the mass transport limitations were overcome in membrane reactor, the processes may find their good applications in water and wastewater treatment.

Enhanced flow electrochemistry for cyclohexane Conversion: From simulation to application

To further improve the capability of flow electrochemistry, the multistage plug-flow electrochemical membrane reactor (PF-ECMR) with membrane electrode was developed for enhancing the oxidation of cyclohexane (CHA) to produce KA oil (mixture of cyclohexanol and cyclohexanone). The catalytic results demonstrated that the CHA conversion and the selectivity to KA oil were up to 95.6% and > 99%, which was the highest in comparison with most of the state-of-the-art catalytic processes reported in the previous works. The mechanism was explored by density functional theory (DFT) calculations, indicating the auxo-action effect of cyclohexanone was beneficial for the formation of cyclohexyl hydroperoxide so as to enhance the CHA conversion. The excellent performance of PF-ECMR was also attributed to the staggered electric field and the accumulative effect of the multi-electrodes. This study provided a successful case of a combination of theoretical prediction and experimental verification together for organic synthesis.

Fabrication of aligned carbon nanofiber doped with SnO2-Sb for efficient electrochemical removal of tetracycline

In recent years, tetracycline (TC) has become an emerging refractory antibiotic pollutant due to excessive use and abuse. The aim of this work is to prepare aligned carbon nanofibrous (ACFs) membrane by electrospinning technology and then dope with SnO2-Sb to electrocatalytic degrade TC. The in-situ growth of SnO2-Sb on the carbon nanofiber surface to fabricate SnO2-Sb/ACFs membrane can increase the oxygen evolution reaction potential and improve conductivity. And the SnO2-Sb/ACFs membrane was used as the anodic membrane of a flow-through mode electrochemical membrane reactor to remove TC in aqueous solutions. The outstanding degradation performance of SnO2-Sb/ACFs membrane on TC was investigated systematically. The results show that the 3-layer SnO2-Sb/ACFs-3 membranes can effectively degrade 20 mg/L TC at an applied potential of 2.5 V. Moreover, SnO2-Sb/ACFs-3 membrane shows excellent degradation stability after 10 cycles of degradation experiments. For exploring the possible TC degradation pathways, HPLC-MS was used to identify the main intermediates during the electrochemical oxidation process. The anodic membrane electrode prepared in this work puts forward a new idea for the safe and efficient degradation of TC.

A Membrane Reactor with Microchannels for Carbon Dioxide Reduction in Extraterrestrial Space

Long-term continuous oxygen supply is of vital importance during the process of space exploration. Considering the cost and feasibility, in situ resource utilization (ISRU) may be a promising solution. The conversion of CO2 to O2 is a key point for ISRU. In addition, the utilization of the abundant CO2 resources in the atmosphere of Mars is an important topic in the field of manned deep space exploration. The Sabatier reaction, Bosch reaction, and solid oxide electrolysis (SOE) are well-known techniques for the reduction of CO2. However, all the above techniques need great energy consumption. In this article, we designed an electrochemical membrane reactor at room temperature based on microfluidic control for the reduction of CO2 in extraterrestrial space. In this system, H2O was oxidized to O2 on the anode, while CO2 was reduced to C2H4 on the cathode. The highest Faraday efficiency (FE) for C2H4 was 72.7%, with a single-pass carbon efficiency toward C2H4 (SPCE-C2H4) of 4.64%. In addition, a microfluidic control technique was adopted to overcome the influence of the microgravity environment. The study may provide a solution for the long-term continuous oxygen supply during the process of space exploration.

Ion Selective Membranes

Ion Selective Membranes

Fabrication of tubular porous titanium membrane electrode and application in electrochemical membrane reactor for treatment of wastewater

In this study, tubular titanium membrane (TTM) /SnO2-Sb/SnO2-Sb-CeO2 porous anode was fabricated and used in continuous tubular membrane reactor for electrochemical treatment of dye wastewater. X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) were used to evaluate the morphology and microstructure of the different tubular titanium membrane. Linear sweep voltammetry (LSV) and accelerated service life test are employed to illustrate the performance of TTM/SnO2-Sb/SnO2-Sb-CeO2 porous membrane electrode. It is found that TTM/SnO2-Sb/SnO2-Sb-CeO2 active layer on titanium membrane has compact microstructure, high over-potential for oxygen evolution (2.10V vs saturated calomel electrode). The effects of pore diameter, applied voltage and flow rate on the electro-catalytic property of the tubular porous electrode were investigated. Study shows titanium membrane reactor with an optimized pore diameter of 10μm has the lowest energy consumption which is important for the practical application of electrochemical technology. The performance of titanium tubular membrane reactor is investigated by treating methylene blue (MB) wastewater under the cell voltage of 3.0–4.5V and the flow rate of 2.5–3.5Lmin−1. This continuous titanium membrane electrochemical reactor using solar cell show excellent performance in treating dye wastewater and the further potential application in electrochemical synthesis.

Review on antibiotics treatment by electrochemical membrane reactor

Lower consumption, higher efficiency, environmental protection, and reliability are the development trends for the treatment of antibiotic wastewater in future. To accomplish this, the electrochemical membrane reactor (ECMR) is developed by combining membrane filtration and electrochemical advanced oxidation technology. The device configuration and working mode of the electrochemical membrane reactor are introduced and compared. Besides, the principles of the removal of antibiotics by the reactor are explained with emphasis. Furthermore, the commonly used cathode and anode materials of the reactor in the current research are summarized, and the electrode materials are discussed. The effects of selection and modification on the elimination of antibiotics in the reactor and the impact are analysed. To address the limitations of electrochemical membrane reactors, this review proposes that more research should be done in the aspects of antibiotic degradation mechanism, reduction of membrane electrode R&amp;D costs, and actual application of amplification devices.

Multiple Effects of Iron and Nickel Additives on the Properties of Proton Conducting Yttrium-Doped Barium Cerate-Zirconate Electrolytes for High-Performance Solid Oxide Fuel Cells

Transition metal oxides have been used as sintering aids for proton-conducting barium cerate-zirconates, which are promising electrolyte materials for low-temperature solid oxide fuel cells (SOFCs) and high-performance electrochemical membrane reactors. However, the effects of the additives on properties other than the density of the electrolytes have been ignored. Here, we report our findings that transition metal additives also affect the electrical properties, stability, and even catalytic activity of proton-conducting ABO3-type perovskites. BaCe0.7Zr0.1Y0.2O3-δ (BCZY) is selected as the basic material, and 2 mol % of Ni1-xFex (x range: from 0 to 1.0) oxides and 4 mol % of FeO1.5 are, respectively, added into BCZY to prepare electrolytes of anode-supported SOFCs. All of the electrolytes with additives can be densified after sintering at 1400 °C for 5 h, while BCZY without additive is porous. X-ray diffraction (XRD) spectra show that Ni and Fe are doped into the lattice of BCZY. For the first time, we find a positive function of Fe additive in BCZY that it not only acts as a good sintering aid but also improves the electrical performance and stability of the BCZY electrolyte in CO2 and H2O at reduced temperatures. The cell with the 2 mol % Ni0.5Fe0.5-doped BCZY electrolyte, with an unoptimized cathode, gives a power density of 973 mW cm-2 at 700 °C, 120 mW cm-2 at 450 °C, and 45 mW cm-2 at 350 °C. It operates under a constant current of 800 mA cm-2 at 650 °C for over 200 h, during which the voltage decreases from 0.73 to 0.71 V. A newly discovered densified layer, formed in the cathode during the SOFC operation, may cause the degradation.

Electrolytic deuteration of unsaturated bonds without using D2

Site-selective deuteration of C–H bonds increases the lifetime and efficacy of drug molecules. Although effective methods to form C(sp2)–D bonds are known, processes for making C(sp3)–D bonds often have low site selectivity, require expensive and unrecoverable D2 gas, or use stoichiometric reagents. Here we report cost-efficient and site-selective reductive deuteration using a tandem electrochemical chemical palladium membrane reactor. This architecture mediates the chemical reaction of deuterium atoms (derived from reusable D2O in an electrochemical compartment) with alkynes, aldehydes and imines. The formation of C(sp3)–D and C(sp2)–D bonds in the isolated chemical compartment is made possible by the deuterium-selective permeability of the membrane that partitions the electrochemical compartment from the chemical compartment. We have utilized the reactor for the deuteration step in the construction of a common drug, cinacalcet, to demonstrate that this method can be used to incorporate deuterium atoms in a pharmaceutical. The reductive deuteration of unsaturated hydrocarbons is a promising deuterium-labelling strategy, although it requires expensive gaseous D2 or other stoichiometric reagents. Here, an electrocatalytic palladium membrane reactor is employed to selectively generate C(sp3)–D bonds via reduction of unsaturated compounds using D2O.