a DoE Energy Frontier Research Center

Enhanced Separation and Mitigated Plasticization in Membranes using Metal-Organic Framework Nanoparticles

The implementation of membranes for ethylene/ethane separations is challenging due to low membrane selectivities under both pure and mixed-gas conditions. Traditional approaches of compositing membranes do not yield improved ethylene/ethane performance, because they rely on a size-sieving based mechanism. Here, the improved adsorption selectivity in M2(dobdc) nanoparticles is instead leveraged to improve membrane permselectivity. The open-metal sites in the metal-organic framework pores selectively adsorb ethylene, increasing the total concentration of ethylene in the film relative to ethane. This leads to an increase in permselectivity as well as permeability in the case of Ni2(dobdc) and Co2(dobdc), while the permeability greatly increases in the case of Mg2(dobdc) and Mn2(dobdc) but a slight decrease in selectivity is observed.

Systematic Tuning and Multi-Functionalization of Covalent Organic Polymers for Enhanced Carbon Capture

A systematic strategy is proposed for preparing multi-functionalized covalent organic polymers (COPs) using the efficient Ullmann cross-coupling reaction. Using this strategy, 17 novel multiblock COPs were synthesized with finely-tuned porosities from a core tetrahedral linker, tetrakis(4-bromophenyl) methane (TBM), and a variety of aromatic linear, trigonal, and even tetragonal linkers. The COPs synthesized in this work have remarkably high porosities and hydrothermal stabilities, which are critical for the adoption of these materials for industrial applications. By tailoring the length and geometry of building blocks, it is possible to tune the BET specific surface areas (SSAs) and pore volumes of these COPs. As a result, the material COP-20 (composed of TBM + DB-OH) has been synthesized with the largest measured pore volume in the field of porous organic materials (3.5 cm3·g-1).

Layered ZIF-Polymer Membranes Through On-Polymer Chemical Transformations of Colloidal Nanocrystal Films

Here it is shown that sub-micron coatings of zeolitic imidazolate frameworks (ZIFs) and even ZIF-ZIF bilayers can be grown directly on polymers of intrinsic microporosity from zinc oxide (ZnO) nanocrystal precursor films, yielding a new class of all-microporous layered hybrids. The ZnO-to-ZIF chemical transformation proceeded in less than 30 min under microwave conditions using a solution of the imidazole ligand in N,N-dimethylformamide (DMF), water, or mixtures thereof. By varying the ratio of DMF to water, it was possible to control the morphology of the ZIF-on-polymer from isolated crystallites to continuous films.

Covalent Organic Frameworks Comprising Cobalt Porphyrins for Catalytic CO2 Reduction in Water

In this work, the concepts of molecular homogenous and heterogeneous catalysis were merged as illustrated by incorporation of molecular CO2 reduction catalysts into the backbone of a spatially well-defined covalent organic framework. This prototype system gives exceptionally high activity (turnover number 290,000, and turnover frequency 9,400 h-1) as well as selectivity over competing proton reduction even in pH 7 water. Covalent organic frameworks (COFs) were chosen instead of the more intensively studied metal organic frameworks (MOFs) owing to the high degree of conjugation and pi-pi stacking between layers in the former, which result in higher charge-carrier mobilities than found in MOFs.

Novel CO2 Binding Mechanism Determined Via in-situ X-ray Absorption Spectroscopy & Theory

X-ray absorption spectroscopy (XAS) probes the local partial density of molecular orbital states around distinct absorbing atoms, and thus provides unique information about the location and chemical nature of the CO2 adsorption process in metal-organic frameworks (MOFs). The figure shows absorption spectra of the nitrogen and oxygen in diamine-appended Mg2(dobpdc); in each case the blue and red spectra represent the MOF without and with adsorbed CO2 present, respectively. Arrows indicate significant spectral changes. First principles theoretical spectra for distinct CO2 adsorption models were also calculated. Three different models had been proposed for the adsorption of CO2 in this MOF, and by comparison of measured and computed spectra for these models we learned that only the insertion model accounts for the observed spectral changes.

Ultrastable Polymolybdate-Based Metal-Organic Frameworks as Highly Active Electrocatalysts for Hydrogen Generation

Metal-organic frameworks (MOFs) exhibit permanent porosity and high surface area, which may provide advantages toward catalytic reactions. Polyoxometalate (POM) ions with redox activity show great promise as redox catalysts, while POM-based MOFs combine the redox nature of the POM moiety and the porosity of a MOF structure, which may favor hydrogen generation. Herein are reported two novel POM-based MOFs, NENU-500 and NENU-501. These materials exhibit not only good air-stability but also tolerance to acid and base media (from pH = 1-12). Furthermore, NENU-500 shows the highest activity for electrochemical hydrogen generation from acidic water among all MOF materials.

Understanding Small Molecule Interactions in Metal-Organic Frameworks: Coupling Experiment with Theory

With separation processes consuming an estimated 10-15% of global energy and the expectation that this consumption will greatly increase with population growth and the implementation of large-scale carbon capture and sequestration technologies, there are intensive scientific efforts focused on the development of new physical adsorbents that might enable more energetically favorable gas separations relative to traditional distillation or absorption processes. This feat is not easy, as the differences in the molecules of interest, such as CO2 and N2 -The main components in a postcombustion flue gas- are minimal. As such, these separations require tailor-made adsorbent materials with molecule-specific chemical interactions on their internal surface. Metal-organic frameworks (MOFs) have gained much attention as next generation porous media for gas separations and storage, and new MOFs are regularly reported.

Photochromic MOFs for Control of Singlet Oxygen Generation

The controlled generation of singlet oxygen is of great interest owing to its potential applications, including industrial wastewater treatment, photochemistry, and photodynamic therapy. Two photochromic metal-organic frameworks (or porous coordination networks), PC-PCN and SO-PCN, were developed. A photochromic reaction was successfully realized in PC-PCN while maintaining its single crystallinity. In particular, as a solid-state material that inherently integrates the photochromic switch and photosensitizer, SO-PCN demonstrated reversible control of 1O2 generation.

About the CGS

Who We Are

The Center for Gas Separations is one of 32 Energy Frontier Research Centers funded by the Department of Energy to conduct fundamental research that addresses the five Basic Energy Sciences Grand Challenges:

  1. How do we control material processes at the level of electrons?
  2. How do we design and perfect atom- and energy-efficient synthesis of revolutionary new forms of matter with tailored properties?
  3. How do remarkable properties of matter emerge from complex correlations of the atomic or electronic constituents and how can we control these properties?
  4. How can we master energy and information on the nanoscale to create new technologies with capabilities rivaling those of living things?
  5. How do we characterize and control matter away -especially very far away- from equilibrium?

The Center is made up of researchers across the US, at the University of California, Berkeley (lead institution), Lawrence Berkeley National Lab, Texas A&M University, University of Minnesota, the National Energy Technology Laboratory, and the National Institute of Standards and Technology.

What We Do

Although it is challenging to calculate the energy used by all chemical separation processes, the best estimates indicate that they account for 10-15% of the energy consumed globally. Some of the largest offenders are the purification of oxygen (O2, 91% of energy input is for separating N2), petroleum refining (>50% energy expended is for separations), and the separation of carbon dioxide (CO2) from H2 necessary for ammonia production (25% of energy consumed). In the US alone, separations account for an even greater ~22% of the total national energy input. Furthermore, when faced with climate change resulting from continually-increasing anthropogenic CO2 emissions and the corresponding necessity of large-scale carbon capture and storage, the cost of separations is expected to increase significantly. Reducing the total energy costs of separations would therefore contribute substantially to minimizing wasteful energy consumption globally.

To address this need, the primary goal within the Center for Gas Separations (CGS) is to tailor-make novel materials for highly efficient gas separations, with an emphasis on adsorbents that are highly selective for CO2 capture. This strategy addresses the 2nd Grand Challenge and requires a fundamental understanding of materials properties, molecular interactions, and the design of adsorbents tuned precisely for interactions with specific gases.


June 2016
2016 All-Hands Meeting
Date: November 8-9, 2016
Location: DoubleTree Hilton at the Berkeley Marina
Reminder: November 8th is Election Day. Don't forget to make arrangements to vote by mail before arriving at the meeting!
March 2015 Materials Chemistry: Cooperative Carbon Capture (Nature News & Views, 519, 294-295, March 19, 2015)
April 2015 Materials Science: The Hole Story (Nature: News Feature, 520, 148-150, April 8, 2015)
March 2015 Porous Crystal Supersuckers Capture Carbon (IEEE Spectrum, March 18, 2015)
March 2015 New Material Captures Carbon at Half the Energy Cost (Phys.org, March 11, 2015)
March 2015 New Material Captures Carbon at Half the Energy Cost (Science Daily, March 11, 2015)
March 2015 New Material Captures Carbon at Half the Energy Cost (Scicasts, March 11, 2015)
March 2015 A Better Way To Scrub CO2 (Science 2.0, March 19, 2015)
March 2015 A Better Way of Scrubbing CO2 (Newswise, March 17, 2015)
March 2015 A Better Way of Scrubbing CO2 (Lab Manager, March 19, 2015)
March 2015 Researchers Triple CO2-Scrubbing Capacity of MOFs by Appending a Diamine Molecule (Azonano, March 18, 2015)
March 2015 A Better Way of Scrubbing CO2 (Nanowerk, March 17, 2015)
March 2015 A Better Way of Scrubbing CO2 (EurekAlert! March 17, 2015)
March 2015 A Better Way of Scrubbing Carbon Dioxide (R&D Mag, March 17, 2015)
March 2015 Cooperative Insertion of CO2 in Diamine-appended Metal-organic Frameworks (Bioportfolio, March 11, 2015)
March 2015 A Better Way of Scrubbing CO2 (Innovations Report, March 18, 2015)
March 2015 New Material Captures Carbon at Half the Energy Cost (Health Medicinet, March 2015)
March 2015 Material Captures Carbon at Half the Energy Cost (Product Design & Development, March 13, 2015)
March 2015 Cooperative Capture (Nature podcast interview of Jeff Long on work reported in 3/12/15 Nature article)
March 2015 The Proof Is in the Pores (EFRC Newsletter, March 2015)
March 2015 Predicting Cheaper Routes for Carbon Capture (EFRC Newsletter, March 2015)
December 2014 Cover of Chemical Science (Chem. Sci., Dec. 2014)
November 2014 Playing Catch and Release with Molecules (Frontiers in Energy Research, Nov. 2014)
October 2014 New Carbon Capture Method is the Best of Both Worlds (Nature World News, Oct. 2014)
October 2014 Un captage de carbone (encore) plus rentable et plus efficace ? (Enerzine, Oct. 2014)
October 2014 MOF Slurry-Based Process May Revolutionize Carbon Capture (Azonano, Oct. 2014)
October 2014 A Cost-effective and Energy-efficient Approach to Carbon Capture (Science Newsline, Oct. 2014)
March 2015 A Cost-effective and Energy-efficient Approach to Carbon Capture (Phys.org, Oct. 2014)
October 2014 New 'Slurry' Could Make Carbon Capture More Efficient (Climate Central, Oct. 2014)
October 2014 A Cost-effective and Energy-efficient Approach to Carbon Capture (e! Science News, Oct. 2014)
October 2014 A Cost-effective and Energy-efficient Approach to Carbon Capture (Science Daily, Oct. 2014)
October 2014 A Cost-effective and Energy-efficient Approach to Carbon Capture (USA News, Oct. 2014)
October 2014 A Cost-effective and Energy-efficient Approach to Carbon Capture with MOFs (Nanowerk, Oct. 2014)
September 2014 New Sorbents for Greener Cooling (C&EN, Sept. 2014)
June 2014 An Inside Look at a MOF in Action (ALS Highlight, June 2014)
April 2014 MOFs (MRS-TV video, April 2014)
December 2013 Research Highlight: Cage Calculations (Nature Chemistry, Dec. 2013)
August 2013 New method predicts adsorption in carbon dioxide-scrubbing materials (R&D Magazine, Aug. 2013)
August 2013 Cover of Advanced Materials (Adv. Mat., Aug. 2013)
June 2013 Cover of the Journal of Physical Chemistry C (J. Phys. Chem. C, June 2013)
May 2013 Material That Sorts Molecules by Shape Could Lower the Price of Gas (MIT Technology Review, May 2013)
April 2013 Researchers discover materials to transform methane into fuel (The Daily Californian, April 2013)
April 2013 Methane-gobbling material found, scientists say (NBC News, April 2013)
April 2013 Inside back cover of Angewandte Chemie (Angewandte Chemie, April 2013)
December 2012 MOFiosos: Berkeley scientists make carbon a structure it cannot refuse (Berkeley Science Review, Dec. 2012)
November 2012 Cover of ChemPhysChem (ChemPhysChem, Nov. 2012)
October 2012 Nanosolutions for Grand Challenges (EFRC Newsletter, Oct. 2012)
October 2012 News and Views in Nature Chemistry: Force fields for carbon capture (Nature Chemistry, Oct. 2012)
October 2012 Cover picture on Angewandte Chemie (Angewandte Chemie, Oct. 2012)
September 2012 Biomimetic And Extreme Surface-Area Frameworks (C&EN, Sept. 2012)
August 2012 Cover of PCCP (PCCP, Aug. 2012)
May 2012 Computer Model Pinpoints Prime Materials for Efficient Carbon Capture (Science Daily, May 2012)
May 2012 New Materials could Reduce Parasitic Load of CO2 Capture by up to 40%, Researchers Say (GHG Monitor, May 2012)
May 2012 New Materials Could Cut Parasitic Energy Costs for CO2 Capture by up to 30-40% (Green Car Congress, May 2012)
April 2012 A Step Up for Separating Hydrocarbons (C&EN, April 2012)
March 2012 New Material Cuts Energy Costs of Separating Gas for Plastics and Fuels (e! Science News, March 2012)
March 2012 Cutting the Cost for Commercial Gas Purification -Theory Leads the Way for a Materials Solution (DOE-BES highlight, March 2012)
March 2012 Carbon Dioxide Catchers (Nanowerk, March 2012)
August 2011 Inside front cover of Advanced Materials (Advanced Materialds, Aug. 2011)
October 2010 Structure of the Week - # 10 October 25, 2010 (ACS, Oct. 2010)
September 2011 Metal Organic Frameworks (CEN Online video, Sept. 2011)
July 2010 Carbon Smackdown: Carbon Capture (Berkeley Lab video, July 2010)
May 2010 Hunt for Improved Carbon Capture Picks up Speed (Berkeley Lab video, May 2010)
February 2010 Carbon Cycle 2.0: Carbon Capture (Berkeley Lab video, Feb. 2010)