About

Omar Farha is the Charles E. and Emma H. Morrison Professorship in Chemistry and also holds a courtesy appointment in Chemical and Biological Engineering at Northwestern University. His research focuses on solving challenging problems in chemistry and materials science, with applications spanning energy, environment, and national defense. He employs atomically precise functional materials, particularly exploring the modular nature of metal–organic frameworks (MOFs) and porous organic polymers (POPs). His work aims to understand how the three-dimensional architecture of these materials influences their functions, which include gas storage and separation, catalysis, water remediation, and detoxification of chemical warfare agent simulants. Dr. Farha's contributions are characterized by fundamental insights into material design and application, advancing the development of innovative solutions for societal and environmental challenges.

Research topics

• Chemistry
• Materials science
• Organic chemistry
• Nanotechnology
• Composite material
• Engineering
• Computer Science
• Environmental chemistry
• Biochemistry
• Metallurgy
• Physical chemistry
• Artificial Intelligence
• Chemical engineering
• Environmental science
• Chemical physics
• Environmental engineering
• Biochemical engineering
• Thermodynamics
• Business
• Photochemistry
• Optics
• Process engineering
• Combinatorial chemistry
• Inorganic chemistry

Selected publications

• Exploring allomelanin: A comparative analysis via natural product extraction and synthesis

  Science Advances · 2026-02-13

  articleOpen access

  Allomelanin is a nitrogen-free class of melanin commonly found in plants and fungi. Although synthetic analogs have been developed from 1,8-dihydroxynaphthalene (1,8-DHN), detailed physicochemical comparisons with natural allomelanins remain limited. Herein, we extracted allomelanin from black knot fungus, chaga mushroom, and black oat using an acid-base extraction protocol, comparing them against a library of synthetic analogs derived from a range of putative, natural precursors. Spectroscopic analyses indicate that simple homopolymerization of 1,8-DHN does not adequately represent natural allomelanin structures. Instead, heterogeneous copolymerization of 1,8-DHN with catechol or tannic acid yields materials with physicochemical properties more consistent with natural extracts. This is also supported by their enhanced antioxidant and dye/metal adsorption properties. Like their synthetic counterparts, extracted natural allomelanins exhibit intrinsic porosity, reaching a Brunauer-Emmet-Teller area of 155 square meters per gram, potentially facilitating nutrient transport and toxin adsorption, although further studies will be required to probe this.

  PublisherDOI

• Boron Cluster Oriented Superhydrophobic Surfaces

  ChemRxiv · 2026-05-06

  articleOpen access

  Hydrophobic coatings are critical for applications spanning anti-fouling and selfcleaning technologies. Conventional fluorinated materials rely on complex fabrication methods and often lack mechanical robustness and scalability. Here, we report a new class of solution-processable fluorinated coatings based on atomically precise closo-dodecaborate clusters densely functionalized with fluorinated carbon chains. Our approach to fabricating these boron oriented superhydrophobic surfaces (BOSS) coatings is based on flexible chemical design, allowing for tailored functionalization and easy scalability. This molecular design enables unprecedented chain packing density, yielding coating with surface free energy around 13 mJ/m2 and excellent water repellency. The coatings exhibit thermally triggered, controllable degradation, along with electrochemical activity, fire retardancy, and mechanical durability when applied to common substrates, providing a viable alternative to conventional fluoropolymer systems. Our findings establish three-dimensional boron cluster as effective scaffold for high-density functional group incorporation, enabling the design of robust, next-generation advanced coatings.

  PublisherDOI

• Oxidation, Oligomerization, Isomerization of Hydrocarbons Using Metal–Organic Frameworks

  ACS Energy Letters · 2026-01-29

  articleSenior authorCorresponding

  The selective conversion of hydrocarbons into higher-value fuels and feedstocks is essential to the global energy and chemistry landscape. While porous inorganic materials have enabled significant progress in these transformations, achieving high activity, selectivity, and stability under industrially relevant conditions remains challenging. Metal–organic frameworks (MOFs) are a promising platform to precisely control active-site environments and interrogate structure–function relationships due to their crystallinity, tunability, and porosity. This review highlights relevant hydrocarbon transformations and outlines the general mechanisms for oxidation, oligomerization, and isomerization. Metal node acidity, confinement effects, and active site dispersion are analyzed for their impact on reactivity and selectivity across the three reactions. Finally, we discuss current limitations in catalyst stability and offer a perspective on integrating reticular chemistry with high-throughput experimentation and machine learning to accelerate the discovery and design of robust, next-generation MOF catalysts.

  PublisherDOI

• Structure–Property Relationships for Moisture-Swing Direct Air Capture

  Environmental Science & Technology · 2026-04-10

  article

  Efficient, low-cost atmospheric CO2 capture is essential for scaling negative-emission technologies. Moisture-swing carbon capture─which adsorbs CO2 from dry air and releases it under humid conditions─offers a low-energy alternative, yet the structure–property relationships governing its performance remain underexplored. Here, we systematically investigate humidity-driven capture on strong-base ion-exchange resins (IERs), varying polymer backbones (acrylic vs styrenic), ammonium functionality (Type I vs Type II), pore architecture (gel-type vs macroporous), and counteranion (dibasic phosphate vs carbonate) across 10 commercial resins. Thermodynamic and kinetic behaviors were assessed via closed-loop cycling with ambient CO2 at 20–70% RH. Morphological and chemical properties were characterized by SEM/EDS, N2 sorption, NMR cryoporometry, and solid-state NMR and FTIR spectroscopies. Macroporous IERs outperformed gel-type analogues in capacity and kinetics, but only when possessing intermediate-sized, well-connected pores, with the phase lag scaling inversely with the pore size. Ion identity and ammonium functionality acted jointly: Type I and Type II IERs exhibited higher swing capacities with phosphate and carbonate loadings, respectively. Anion choice also governed the kinetics, with phosphate slowing adsorption and carbonate slowing desorption. Acrylic backbones drove greater water uptake than styrenic ones. Solid-state NMR revealed humidity-driven protonation, consistent with the proposed swing mechanism. Together, these findings provide practical design rules for improving direct air capture via moisture-swing sorbents.

  PublisherDOI

• Machine Learning Interatomic Potentials for Modeling Framework Flexibility and Water Uptake in NbOFFIVE-1-Ni Metal-Organic Framework

  ChemRxiv · 2025-12-16

  articleOpen access

  Metal-organic frameworks (MOFs), with their distinctive porous structures and tunable chemical properties, have shown immense promise in the separation and storage of gases. Currently, the accurate simulation of their adsorptive properties remains challenging, especially for systems where the molecules fit very tightly in the pores. Traditional simulation methods often approximate the frameworks as rigid and do not account for the framework flexibility seen in materials such as NbOFFIVE-1-Ni. First principles molecular dynamics (FPMD) simulations offer the desired accuracy in modeling this flexibility but are limited by their extensive computational demands, rendering them impractical for long simulations. Conversely, classical force field-based simulations offer computational efficiency but lack the necessary accuracy. To break this accuracy-efficiency trade-off, we have developed machine-learning interatomic potentials (MLIPs) trained on energies and forces from FPMD to model the framework flexibility of NbOFFIVE-1-Ni in the presence of water over nanosecond timescales. Furthermore, by integrating MLIP-driven MD (MLIP-MD) with grand canonical Monte Carlo (GCMC) simulations, we further incorporated framework flexibility into adsorption predictions, yielding water adsorption isotherms that better align with experimental data compared to conventional GCMC simulations. These advances offer new opportunities for the design and optimization of MOFs in gas storage and separation applications.

  PublisherDOI

• Hierarchical Design of COFs via NHC-Grafting for Selective Gold Recovery from E-Waste: Experimental and MD Analyses

  Journal of the American Chemical Society · 2025-10-10 · 15 citations

  article

  In this study, a highly crystalline imine-linked covalent organic framework (COF) was synthesized via Schiff base condensation, followed by postsynthetic modification (PSM) to introduce N-heterocyclic carbene (NHC) ligands. The two-step PSM involved reduction of imine bonds to secondary amines and the subsequent covalent attachment of NHCs, while preserving the COF's crystallinity and porosity. Structural analyses confirmed successful functionalization and high stability of the modified COF. The resulting NHC-functionalized COF demonstrated strong affinity and high selectivity toward Au ions, making it a promising adsorbent for efficient gold recovery from complex e-waste matrices. XPS analysis confirmed the selective adsorption of Au(III) ions and their reduction to Au(I) via electron donation from NHC sites, enabling efficient and selective uptake from solution through coordination interactions within the COF matrix. Adsorption analysis demonstrated that Au(III) uptake by COF-NHC follows a PSO-Freundlich model, characterized by rapid adsorption kinetics and heterogeneous surface binding. Molecular dynamics simulations revealed that carbon functional groups within the postsynthetically modified COF play a crucial role in stabilizing and potentially reducing gold ions, underscoring the framework's effectiveness for selective gold recovery from e-waste.

  PublisherDOI

• Programming Local Confinements in Crystalline Frameworks through Reticular Chemistry

  Research Square · 2025-12-01

  preprintOpen access1st authorCorresponding
  PublisherOA PDFDOI

• 33 Unresolved Questions in Nanoscience and Nanotechnology

  ACS Nano · 2025-09-04 · 22 citations

  articleOpen access

  Significant advances in science and engineering often emerge at the intersections of disciplines. Nanoscience and nanotechnology are inherently interdisciplinary, uniting researchers from chemistry, physics, biology, medicine, materials science, and engineering. This convergence has fostered novel ways of thinking and enabled the development of materials, tools, and technologies that have transformed both basic and applied research, as well as how we address critical societal challenges. In this Nano Focus, we pose and explore 33 questions whose answers could profoundly impact fields such as energy, electronics, the environment, optics, and medicine. These questions highlight the need for deeper foundational understanding, improved tools and techniques, and innovative applications─each with significant societal relevance. Together, they represent a global call-to-action for the scientific community.

  PublisherOA PDFDOI

• Electrocatalytic Hydrogenation with MOF-derived Cobalt Nanoparticles

  ChemRxiv · 2025-10-08

  preprintOpen access

  Electrochemical hydrogenation (e-H) of organic substrates represents a key transformation for advancing industrial electrification and sustainable chemical manufacturing. Here, we represent e-H of acetone and pyridine by cobalt nanoparticles derived from a Co-based MOF. A novel two-dimensional cobalt metal–organic framework, Co-L0-NS, featuring a kgd-type layered topology with Co(II) paddlewheel nodes and polyaromatic linkers, has been synthe-sized and structurally characterized. Electrochemical reduction of Co-L0-NS induces controlled framework recon-struction, producing highly dispersed cobalt nanoparticles that efficiently catalyze the e-H of acetone to isopropanol and show moderate activity toward pyridine reduction to piperidine. In contrast, electrodeposition from aqueous Co²⁺ precursors forms larger, more crystalline metallic Co particles. Spectroscopic and electrochemical analyses, sup-ported by Tafel modeling, indicate a proton-coupled electron-transfer (PCET) mechanism with a rate-determining step exhibiting a Tafel slope of ~150 mV dec⁻¹. These findings highlight how structural features of the parent MOF—open Co sites, two-dimensional connectivity, and redox flexibility—govern nanoparticle formation and catalytic be-havior, providing design principles for MOF-derived cobalt electrocatalysts.

  PublisherDOI

• Examining Metal Identity and Proximity Effects on Acetylene Hydrogenation with Azolate-Based MOFs

  ACS Applied Materials & Interfaces · 2025-12-05

  articleSenior authorCorresponding

  Liquid organic hydrogen carriers (LOHCs) are an attractive fuel source due to their compatibility with existing transportation methods and ease of use. However, they suffer from sluggish (de)hydrogenation kinetics. One promising platform for developing next-generation catalysts is metal–organic frameworks (MOFs), which can enable systematic interrogation into the influence of metal identity and spatial arrangement. In this study, the effect of the coordination environment was investigated using Ni- and Co-based azolate MOFs: MFU-4l-OH (MxZn5–x(OH)4(BTDD)3; x = 4 for M = Co and x = 3 for M = Ni, H2BTDD = bis(1H-1,2,3-triazolo[4,5-b][4′,5′-i])dibenzo[1,4]dioxin), composed of single-site nodes, and M(OH)2BBTA (M = Ni, Co; H2BBTA = 1H,5H-benzo(1,2-d:4,5-d’)bistriazole), composed of extended chain-type nodes. The catalysts were characterized by isotherms, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES), and X-ray photoelectron spectroscopy (XPS) analysis. Acetylene hydrogenation activity under steady state conditions (150 °C, 1:1 C2H2:H2) revealed higher turnover frequencies (TOFs) up 1.8 × 10–4 min–1 and 3.0 × 10–5 min–1 for Ni-MFU-4l-OH and Co-MFU-4l-OH, respectively, compared to their BBTA analogues. However, the Co-based MOFs, particularly Co2(OH)2-BBTA, exhibited greater selectivity (up to 19%) for the fully hydrogenated ethane product. Isosteric heat of adsorption (Qst) measurements for ethylene and ethane revealed that the BBTA framework had stronger binding to the products than MFU-4l. These findings demonstrate that metal identity and coordination environment may modulate acetylene hydrogenation performance, leading to design principles for tuning LOHC hydrogenation catalysts.

  PublisherDOI

Recent grants

• RAPID: Regenerable Antiviral Nanoporous Materials for Protection

  NSF · $200k · 2020–2022

Frequent coauthors

• Joseph T. Hupp

  874 shared

• Timur İslamoğlu

  Northwestern University

  308 shared

• Randall Q. Snurr

  Northwestern University

  210 shared

• Xingjie Wang

  174 shared

• Xuan Zhang

  Texas A&M University

  173 shared

• J. Fraser Stoddart

  UNSW Sydney

  153 shared

• Zhijie Chen

  143 shared

• Peng Li

  Fudan University

  143 shared

Awards & honors

• Charles E. and Emma H. Morrison Professorship in Chemistry