Despite the importance of wastewater environmental monitoring in disease prevention and response strategies, its use remains poorly documented in Senegal. In addition, there is more onsite sanitation than sewer networks in Dakar, and open drains channel for rainwater are also used as clandestine wastewater discharge into the sea. This study aimed to assess the presence of specific pathogens in wastewater, faecal sludge, and bathing water (the sea). Samples were taken at treatment plants, an open drain, and in the receiving environment (the sea) from June to December 2023. Total nucleic acid was subjected to multiplex qualitative qPCR using SeeGene Allplex™ kits targeting 34 gastrointestinal pathogens. Descriptive statistics, multiple correspondence analysis (MCA) and logistic regression were performed. Considering all matrices, across 51 analysed samples, the results revealed strong bacterial (96.08%, n = 49), parasitic (84.31%, n = 43), and viral (68.63%, n = 35) presence. These results showed high levels of Aeromonas spp. (96.08%), Blastocystis hominis (80.39%), Enterocytozoon (58.82%), and Norovirus GII (74.51%) among bacteria, protozoa, helminths, and viruses, respectively. Moreover, faecal sludge and pumping station samples show more identified pathogen than wastewater treatment plant and seawater samples. The MCA revealed that the dry season is spatially associated with a greater number of pathogens than the rainy season, but the latter showed a greater species diversity. Logistic regression showed that certain physicochemical parameters, including BOD5, turbidity, pH, and suspended solids, influence pathogen detection. However, qualitative detection and sampling period may constitute limitations. These results reveal that wastewater and bathing water can serve as sources of information on the circulation of pathogens of interest with epidemic potential. Therefore, this valuable epidemiological tool could serve as an adjunct to clinical surveillance in order to prevent future epidemics.

Safe sanitation access is commonly believed to be ubiquitous in high-income countries; however, researchers and community advocates have exposed a glaring lack of access for many low-income communities and communities of color across the U.S. While this disparity has been identified and quantified at a high level, local and household-level implications of sanitation failures remain ill-defined. We develop a set of user-based and environmental measures to assess the performance of centralized wastewater systems, septic systems, and straight-piped systems in Lowndes County, Alabama. We combine qualitative, survey, and environmental sampled data to holistically compare user experiences across infrastructure types. This integrated approach reveals new routes of exposure to wastewater through informal household maintenance and system backups and provides evidence for the spread of wastewater-like contamination throughout the community. This work elucidates the severity of sanitation failures in one rural U.S. community and provides a framework to assess sanitation quality in other contexts with limited sanitation access in high-income countries.

Recovering nitrogen (N) from wastewater is a potential avenue to reduce reliance on energy-intensive synthetic nitrogen fixation via Haber-Bosch and subsequent treatment of N-laden wastewaters through nitrification-denitrification. However, many technical and economic factors hinder widespread application of N recovery, particularly low N concentrations in municipal wastewater, paucity of high-efficiency separations technologies compatible with biological treatment, and suitable products and markets for recovered N. In this perspective, we contextualize the challenges of N recovery today, propose integrated biological and physicochemical technologies to improve selective and tunable N recovery, and propose an expanded product portfolio for recovered N products beyond fertilizers. We highlight cyanophycin, an N-rich biopolymer produced by a diverse range of bacteria, as a potential target for N bioconcentration and downstream recovery from municipal wastewater. This perspective emphasizes the equal importance of integrated biological systems, physicochemical separations, and market assessment in advancing nitrogen recovery from wastewater.

Low-impact, closed-loop recycling of plastics is crucial to sustainably managing these pervasive and resource-intense materials. Our approach aimed to reinvent chemical recycling by integrating it with electrochemical processes to generate reactants electrochemically and depolymerize plastic in situ, with the objective of reducing both costs and environmental impacts. We investigated electrochemically mediated alkaline hydrolysis and methanolysis of poly(ethylene terephthalate) (PET) to achieve the following advantages over conventional methods: access to more extreme reactivity from applying an electrochemical driving force, process intensification, and application of more moderate operating conditions. Total PET conversion and product yields were measured to systematically investigate the performance effects of catholyte methanol content, anolyte buffering, and temperature. Leveraging these insights to improve experimental conditions, we achieved 45 mol% PET conversion in 5 hours at ambient pressure and relatively moderate temperature (50 °C) in 0.1 M NaClO4 (100 mol% methanol) catholyte and 0.1 M Na3PO4 anolyte.

Electrochemical nitrate reduction (ENR) is an appealing method for remediating nitrate contamination in wastewater and producing ammonia using renewable electricity. However, a mechanistic understanding of coupled mass transfer and electrocatalysis at the electrode-electrolyte interface, which dictates ENR efficiency, is limited. In this study, we develop an experimentally-validated multiphysics model of the Stern, diffuse, and diffusion layers near the surface of a polycrystalline titanium catalyst to investigate the effect of the electric double layer on ENR. The developed model couples the generalized-modified-Nernst-Planck equation with Frumkin-Butler-Volmer kinetics and numerical optimization to quantify the effect of applied potential and bulk electrolyte concentration on the ammonia formation rate. Our results reveal how dynamic driving forces at the polarized interface give rise to experimentally observed trends in ENR. Guided by this insight, we show that a more negative potential-of-zero-charge increases the limiting current density for ammonia synthesis by enabling faster migration of nitrate towards the cathode surface. The results motivate the development of multi-scale models that link transport phenomena with molecular-scale modelling to design and tailor interfaces for efficient ENR.

The Haber-Bosch process for artificial nitrogen fixation has asymmetrically doubled the input of reactive nitrogen into the global nitrogen cycle. Excess reactive nitrogen can enter surface and coastal waters and harm human, environmental, and aquatic health. The electrochemical nitrate reduction reaction (NO 3 RR) could valorize nitrogen-polluted wastewaters by reducing nitrate (NO 3 - ) into ammonia (NH 3 ), a common fertilizer product. The composition of the interfacial electrolyte at the heterogeneous electrode surface impacts the reaction products. We have found that a high local concentration of NO 3 - and low interfacial pH increases NO 3 RR activity and NH 3 selectivity on titanium 1 . However, with the consumption of NO 3 - and protons from NO 3 RR, this favorable interfacial electrolyte environment is challenging to sustain during electrolysis under a constant applied potential. Pulsed electrolysis, where the applied electrode potential is varied between a cathodic and anodic potential at a given frequency, can dynamically modulate the interfacial electrolyte composition. We have previously demonstrated that pulsed electrolysis increases the selectivity of NH 3 to nitrite (NO 2 - ) by 3.4-fold over potentiostatic operation 1 , suggesting that pulse parameters can tune reaction products. An anodic potential can electrostatically attract nitrate to the electrode surface, and periodic pulses can alleviate accumulated OH - to lower the interfacial pH. We experimentally demonstrate on a model titanium foil catalyst the effect of pulse parameters (anodic potential, anodic duration, cathodic potential, cathodic duration) on the selectivity and Faradaic efficiency of NO 3 RR to NH 3 . To understand the effects of pulse parameters on NO 3 RR mechanisms, we characterize the composition of reaction intermediates in the boundary layer and at the surface using scanning electrochemical microscopy (SECM). We also use electrochemical mass spectrometry (EC-MS) to measure the time-resolved evolution of competing reaction products H 2 and N 2 in response to pulse parameters. Taken together, these results demonstrate the effect of pulse parameters on the enrichment of NO 3 - and protons in the interfacial electrolyte and resulting NO 3 RR activity, providing insight into the optimal operating conditions for NH 3 production. (1) Guo, J.; Brimley, P.; Liu, M. J.; Corson, E. R.; Muñoz, C.; Smith, W. A.; Tarpeh, W. A. Mass Transport Modifies the Interfacial Electrolyte to Influence Electrochemical Nitrate Reduction. ACS Sustainable Chem. Eng. 2023 , 11 (20), 7882–7893.

Electrified interfaces are critical to the performance of energy systems and often demonstrate substantial complexity under operating conditions. A nanoscale understanding of the interfacial microenvironment, i.e., the solid-electrolyte interphase (SEI), in lithium-mediated nitrogen reduction (Li-N2R) is key for realizing efficient ammonia (NH3) production. Herein, we used time-resolved neutron reflectometry (NR) to observe SEI formation under Li-N2R conditions. We found that the LiBF4-based electrolyte provided a substantially more well-defined SEI layer than previous SEI NR interrogations that used LiClO4, highlighting the underlying chemistry that dictates electrolyte design and enabling new NR-based studies. Using in situ NR, we found that the LiBF4-derived SEI under Li-N2R conditions comprises a thick, diffuse outer layer and a thin, compact inner layer at low current cycling (<2 mA/cm2), revealing a structure which ex situ studies have not been able to probe. Increased current cycling and sustained current cycling led to the merging of the layers into a single-layer SEI. We used isotope contrast methods with d6-EtOH and d8-THF to drive time-resolved tracking of SEI growth at low current cycling, revealing that the proton donor modifies the inner layer, and the solvent modifies the outer layer. Li dendritic growth was observed in the absence of a proton donor. Neutron absorption also indicated the presence of boron in the SEI, underscoring the value of neutron-based interrogation. Our results inform Li-based systems and reaction microenvironments, and these methods can be applied broadly to interfacial energy technologies.

William A. Tarpeh, an assistant professor at Stanford University, discusses his career path and how he thinks a multiscale perspective can help tackle the biggest hurdles in water resource recovery.

Recycling lithium-ion batteries (LIBs) can supplement existing supplies of critical materials and improve the environmental sustainability of LIB supply chains. In this work, environmental intensities (greenhouse gas emissions, water consumption, energy consumption) of industrial-scale production of battery-grade cathode materials from used LIBs are compared to the intensities of conventional mining supply chains. Refining mixed-stream LIBs into battery-grade materials reduces these environmental intensities by at least 55%. Electricity consumption is identified as the principal contributor to all LIB recycling environmental intensities, and different electricity sources can change greenhouse gas emissions up to eight times. Supply chain steps that precede refinement (material extraction and transport) contribute marginally to the environmental intensities of circular LIB supply chains (<5%), but are more significant in conventional supply chains (31%). This analysis disaggregates conventional and circular steps based on material extraction, transport, and industrial refinement operations to provide important insights for advancing sustainable LIB supply chains.

Adsorption presents an interesting alternative to traditional phosphorus removal technologies because it excels at achieving low levels of phosphorus (P). One leading adsorption technology is called HAIX (Hybrid Anion Exchanger) and is made from ferric oxide nanoparticles impregnated in a strong base anion exchange resin. This adsorption media, marketed as FerrIX A33E, offers great performance in terms of P removal, but requires substantial quantities of sodium hydroxide (NaOH) and sodium chloride (NaCl) to regenerate. A new version of HAIX (named WBA-2) was previously synthesized using a weak base anionic resin. It showed better regeneration abilities under lower concentrations of NaOH and no NaCl. In this study, breakthrough curves of WBA-2 and FerrIX were compared over three adsorption/regeneration cycles with 0.1 M NaOH as the regenerant solution. FerrIX was able to treat 1630 bed volumes in the first cycle, but only managed to treat 800 bed volumes in the third cycle. WBA-2 was able to keep its full treatment capacity with 1470 bed volumes treated in the first cycle and 1500 for the third. To push the regeneration efficiency of WBA-2 even further, its regeneration was evaluated at 24 degrees C, 50 degrees C and 80 degrees C. Higher temperature during regeneration yielded higher performance with 79 %, 85 % and 91 % +/- 1 % of regeneration efficiency for the three temperatures in increasing order. Finally, this study discusses the possibility of using onsite electrolysis to provide the consumables needed for the regeneration of HAIX, and demonstrates how using higher temperatures during electrolysis and regeneration of HAIX can improve overall operational performance.

The electrochemical reduction of nitrate (NO3R) to ammonia is a bold yet conceivable way of producing ammonia using renewable electricity. However, serious challenges remain in finding optimal electrocatalysts for the process. An atomistic understanding of the surface energetics behind the NO3R is needed in order to design an efficient catalyst. Herein, we combine energetics from density functional theory and microkinetic modeling to demonstrate how surface descriptors can help simplify the search for efficient NO3R electrocatalysts. We illustrate the strong correlations between transition-state energetics and O* binding energies for adsorbed nitrate and nitrite on transition metals. For intermediates from NO* and beyond, we compare the benefits of using either the N* or H* binding energies to predict reduction onset potentials. These insights enable us to develop a simple microkinetic model that elucidates the surface coverages of intermediates and the product selectivity of NO3R across a range of potentials and transition metals. We show that the model adequately corroborates with quasi-steady-state rates observed experimentally.

Refining waste streams into circularized chemical products will be a core tenet of 21 st century chemical engineering; urgent environmental challenges like re-balancing the nitrogen cycle present imperative opportunities for new chemical processes. Aqueous reactive nitrogen discharge to surface waters causes algal blooms that damage aquatic ecosystems and exacerbate climate change. Precluding aqueous pollution by refining these fugitive nitrogen emissions into purified products could simultaneously remediate harmful pollutants and generate 19 billion USD annually. The electrochemical nitrate reduction reaction (NO 3 RR) shows promise to convert wastewater nitrate (NO 3 – ) to purified ammonia (NH 3 ) as a circularized fertilizer. This promise has spurred recent interest in experimental and theoretical NO 3 RR studies focused on improving state-of-the-art catalyst activity and reaction overpotential for conversion to NH 3 . The reactor systems that house these prospective catalysts, and that interface catalytic reactions with separations, are equally important to achieve wastewater treatment and purified chemical recovery, but are underrepresented in literature. In this work, we rationally engineer an electrocatalytic reactive separations unit process called Electrocatalyst-in-a-Box (ECaB) that unites molecularly-precise homogeneous electrocatalysis with rational reactor design to enable energy-efficient refining. Achieving active and selective NO 3 RR in practice is challenged by the often-overlooked dilute nature of -bearing wastewaters. Homogeneous molecular catalysts that exhibit precise substrate and product selectivity are a seemingly obvious remedy this challenge; however, reactor systems capable of catalyst reuse are underdeveloped. This highlights a second challenge: the need to pair reactions with separations to achieve catalyst reuse, removal, and NH 3 recovery. These challenges frame the scope of our study. We focused our investigation on the homogeneous NO 3 RR catalyst Co(DIM) (DIM = 2,3-dimethyl-1,4,8,11-tetraazacyclotetradeca-1,3-diene) because of its perfect selectivity for NH 3 and benchmark intrinsic activity. We elucidated that competitive adsorption between Co(DIM) and Mg 2+ to electrode surfaces dictates observed catalytic activity. Mg 2+ is a common wastewater constituent that impedes activity for homogeneous and heterogeneous catalysts alike. We showed two ways to mitigate Mg 2+ passivation. First, the bulky and positively-charged Co(DIM) complex can preclude Mg 2+ adsorption to cathode surfaces, suggesting that immobilization of Co(DIM) could afford cathode surfaces immune to passivation. Second, Mg 2+ can be mitigated by anion-selective separations. We developed a unit process called ECaB to integrate wastewater extraction, Co(DIM)-mediated NO 3 RR to NH 3 , and NH 3 recovery. ECaB’s novel design characteristics up-concentrate from 2 to 54 mM via Donnan dialysis (an activity gradient creates an electrochemical potential that drives ion exchange) without input electricity, preclude Mg 2+ from cathode surfaces, and enable Co(DIM) reuse. ECaB thus overcomes the challenges of dilute and reactive separations development. Our ECaB experiments set benchmarks for energy efficiency (67 kWh kg-N –1 ) and NH 3 production rate (320 μg-N cm -2 h -1 ) for both homogenous and heterogeneous NO 3 RR systems, which urgently require optimization to compete with incumbent nitrogen management processes. To this end, we used a technoeconomic analysis to quantify the performance gap between ECaB and operationally feasible systems; this yielded scenario-based, tractable partial current density targets. The ECaB system we developed is agnostic to NO 3 RR catalyst and is flexible to homogeneous and heterogeneous catalysts. We developed a lab-scale continuous-mode ECaB reactor system using high flow rate electrolyzers to extract transport-dependent rate constants and rate orders for ECaB’s reaction and separation subunit processes. We then use these subunit rate laws in a full unit process model of ECaB to optimize experimental performance, which in turn validates our model. The continuous ECaB reactor is to be demonstrated this year on a four-acre farm as part of our collaboration with Stanford Earth Systems Science and the USDA. This work showcases the integrated study of seemingly disparate but critically linked fields: fundamental interfacial electrocatalysis and electrochemical engineering affords high-performing reactive separations. Its past and current focus involves iterative investigation at the atomic, interfacial, reactor, and pilot scales. So far, this project has yielded a novel high performing reactor system that, in conjunction with fundamental catalyst development, will accelerate the circular refining paradigm. We hold these efforts as imperatives to improve sanitation access, expand nitrogen commodity access, and offset costs and emissions of industrial ammonia production. Figure 1

Dimensionally stable anodes (DSAs) are widely used for the free chlorine evolution reaction (CER); however, their reliance on expensive platinum group metals limits their widespread adoption. This cost barrier has driven the search for alternative materials that are both effective and affordable. Cobalt antimonate (CoSbxOy) has been identified as a suitable low-cost and effective alternative for CER, but the synthesis parameters that maximize the Faradaic efficiency (FE) have not been elucidated. The FE of an electrode is influenced by its material properties, which are affected by the synthesis conditions. A factorial design study was used to investigate the effects of electrodeposition potential, charge, and the Sb:Co molar ratio of the plating solution on the CER for CoSbxOy electrodes; XRD, XPS, SEM-EDS, and SECM were used to analyze electrode composition. At a deposition potential of -1.005 VAg/AgCl, 2.5 mAh charge, and 4.28 Sb:Co, the greatest FE was achieved. Electrode surface morphology was likely the driving factor for maximizing the FE, which may be attributed to the rate of bubble liberation from the anode surface. In dilute chloride solutions at neutral pH, CoSbxOy anodes exhibited high stability and comparable FE to conventional Ru/Ir electrodes, highlighting their potential as a durable and cost-effective alternative.

A Telluride Science Workshop on electrochemical separations was convened in early 2025. In this Feature, 17 of the workshop participants share their perspectives and future outlooks on this rapidly growing research area.

In molecular electrocatalysis, a log-linear tradeoff between turnover frequency (TOF) and overpotential (η) is frequently observed and limits catalytic performance. This scaling relationship is reflected in the molecularly catalyzed electrochemical nitrate reduction reaction (NO3RR), which generally requires large overpotentials for ammonia production (η > 1.5 V). Thus, strategies to lower η while increasing TOF are needed for more energy-efficient NO3RR. In this study, we investigate the molecular electrocatalyst [CoIII(DIM)Br2]ClO4 (DIM = 2,3-dimethyl-1,4,8,11-tetraazacyclotetradeca-1,3-diene), which selectivity catalyzes NO3RR to NH3. Through electroanalytical studies, we demonstrate that electrolyte pH and bromide concentration can be synergistically tuned to lower η (up to 0.50 V) while increasing TOF (up to 5.2x). We therefore tailor electrolyte composition to achieve a TOF of (5.3 ± 0.4) s−1 at −0.13 V vs. RHE (η ≈ 0.85 V), surpassing both the catalytic activities and overpotentials of state-of-the-art NO3RR molecular electrocatalysts. Our results reveal that tuning electrolyte composition can help overcome the TOF-η tradeoff in molecular electrocatalysis.

Ion exchange shows promise for recovering phosphate from wastewater as value-added products but requires high phosphate selectivity to compete with conventional treatment. Hybrid anion exchange (HAIX) resins, which contain nonselective basic functional groups and selective iron oxide nanoparticles (FeOnp), can remove phosphate from wastewater. However, knowledge gaps remain regarding the mechanisms of phosphate selectivity and influence of competing ions, hindering efforts to model adsorption dynamics and design adsorption processes for varying wastewaters. To address these gaps, we integrated aqueous-phase adsorption analysis with solid-phase, synchrotron-based X-ray characterization; this integration facilitated elucidation of the distribution and speciation of iron, phosphate, and competing anions on HAIX resins. We compared a quaternary ammonium-functionalized HAIX resin (strong base anion exchange, SBA) to a tertiary amine version (weak base anion exchange, WBA) to determine the role of functional groups. X-ray radiography revealed differences in FeOnp speciation (goethite vs ferrihydrite) and distribution (peripheral vs homogeneous) between the resins, resulting in varied phosphate affinity and intraparticle diffusion resistance. Using micro-X-ray fluorescence (μ-XRF) and micro-X-ray absorption near-edge structure (μ-XANES) spectroscopy, we identified differences in where and how phosphate binds across resin types and wastewaters. Across wastewater compositions, FeOnp sites in WBA contribute more to phosphate adsorption than in SBA, possibly due to variations in Fe distribution and speciation. Phosphate adsorption densities calculated from quantitative μ-XRF maps matched those from aqueous analysis, demonstrating the effectiveness of this integrated approach. Overall, results demonstrate the use of synchrotron-based X-ray characterization for investigating adsorption mechanisms and advance HAIX as a phosphate recovery technology from wastewaters.

Selective membrane separation processes can recover ammonia from wastewaters and advance a circular nutrient economy. E. coli AmtB (EcAmtB) is a well-characterized and ammonium-selective membrane protein that could be embedded into synthetic membranes. However, the effects of phospholipids present in E. coli membranes, namely 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG), on EcAmtB folding and function remain undetermined. Solid supported membrane-based electrophysiology (SSME) was conducted to observe ammonium migration through EcAmtB proteoliposomes containing varying compositions of phospholipids POPE, POPG, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (POPA). In contrast to previous literature support in favor of POPG, this study found that proteoliposomes containing POPE adhered to SSME sensors exhibited the highest total ammonium permeability (2498 pA of total sensor current or 15.59 billion cations per second). A crucial phospholipid head group bonding site may be the E70 location, a glutamate at the junction of two protein subunits. Understanding how phospholipid-protein bonding determines transport performance will aid in developing similar protein-synthetic membrane bonding structures for industrial selective recovery processes.

Ion-selective membranes could enable sustainable critical material separations processes because of their scalability, low energy consumption, and low chemical input. The effects of membrane water content and incorporation of ion-coordinating ligands have been studied via computation and experiment to develop structure-performance relationships. However, few studies systematically investigate the effects of membrane composition beyond monomer chemical identity or the balance of driving forces such as diffusion and electromigration. Here we synthesized a library of poly(ethylene glycol) acrylate membranes with varying percentages of ion-coordinating monomers (acrylic acid, 4-vinylpyridine) to investigate the influence of ligand content on ion permeabilities and permselectivities. Trends in membrane performance under electrodialysis and diffusion were compared to elucidate the relative effects of separation driving forces and to inform electrochemical operation. We observed order-of-magnitude permeability reductions with ligand content for ions capable of multidentate ligand complexation, especially for nickel in the pyridine-containing membranes. As a result, lithium/nickel permselectivity gradually increased by a factor of 1.65× from 10 to 50 mol% pyridine membranes. We further demonstrated simultaneous improvements in lithium/nickel separation productivity (1.75×) and selectivity (2.99×) with increasing electric potential driving force. Ultimately, results from this study provide design insights for ligand-functionalized membranes in electrified ion-ion separations processes.

An emerging design heuristic for electrochemical nitrate reduction (NO3RR) catalysts is synthesizing electron-deficient sites to facilitate binding of electron-rich NO3-. However, this rule has rarely been applied to metal-, nitrogen-doped carbon (MNC) catalysts. Titanium (Ti), with low electronegativity and high NO3RR reactivity, is a compelling MNC candidate. To date, atomically dispersed TiNx motifs have eluded synthesis due to the strong oxophilicity of Ti. Here, we leverage nitrogen-rich carbon flowers (CF) to overcome synthetic challenges and produce Ti-, N-doped carbon flower (TiCF) catalysts. Advanced materials characterization demonstrates that TiCF catalysts are a mixed phase material with 3/4 of Ti atoms in TiO2-like nanoparticles and 1/4 of Ti atoms in novel, atomically dispersed TiNx sites. TiCF achieves 61 ± 7% NH3-selectivity at -0.70 V vs RHE and 14 ± 5 mA/cm2 to NH3 formation (|jNH3|) at -0.85 V vs RHE in (0.1 M NaOH + 0.1 M NaNO3 + 0.45 M Na2SO4) electrolyte. Control studies show both CF morphology and Ti sites are essential for high NO3RR activity. Density functional theory calculations attribute the NO3RR reactivity to TiNx, which facilitates multiple bond formation with surface intermediates to promote favorable NH3 synthesis pathways. Thus, TiCF exhibits 60× higher |jNH3| values than bulk Ti and NH3 yield rates (>0.06 mmol NH3/h/cm2) that are competitive with state-of-the-art MNC catalysts (e.g., FeNC, CuNC). TiCF introduces a new class of Ti electrocatalysts, advancing the MNC design space and sustainable NH3 production.