graduate student, Texas A&M University
cost effective high yield capture of CO2 from industrial flue gas before it gets into the atmosphere
I am an inorganic chemistry graduate student at Texas A&M University. The area of research in which I work are metal organic frameworks and porous polymer networks for gas capture or storage, novel catalysis, fundamental functionality studies, and their industrial application development. My research group works with companies to implement our work as commercially available products. My research within my group focuses more heavily on porous polymer networks which do not contain any metallic components. More specifically, this research project focuses on selectively capturing carbon dioxide, a major component of global warming, from industrial flue gas prior to its entry into the atmosphere. To do this, we use a cost effective, non-toxic, amine-loaded porous polymer network (PPN) that can be recycled and reused for carbon dioxide capture multiple times with little to no environmental hazards. This PPN system can be regenerated at low temperatures and is thus more energy efficient than current industrial methods for carbon dioxide capture which involve water based amine solutions which require energy intensive regeneration. In addition, these high energy demands often result in corrosive or toxic amines being released into the environment. The PPN system in my research is more environmentally friendly, more energy efficient, and cheaper than the current industrial methods used for carbon dioxide capture. This PPN system can also be made on a large scale and has great potential to make a difference in the fight against global warming.
Abstract: Metal-organic frameworks (MOFs), also known as coordination polymers, are formed by the self-assembly of metallic centres and bridging organic linkers. In this critical review, we review the key advances in the field and discuss the relationship between the nature and structure of specifically designed organic linkers and the properties of the products. Practical examples demonstrate that the physical and chemical properties of the linkers play a decisive role in the properties of novel functional MOFs. We focus on target materials suitable for the storage of hydrogen and methane, sequestration of carbon dioxide, gas separation, heterogeneous catalysis and as magnetic and photoluminescent materials capable of both metal- and ligand-centred emission, ion exchangers and molecular sieves. The advantages of highly active discrete complexes as metal-bearing ligands in the construction of MOFs are also briefly reviewed (128 references).
Pub.: 16 Sep '11, Pinned: 29 Jun '17
Abstract: The carbonized PAF-1 derivatives formed by high-temperature KOH activation showed a unique bimodal microporous structure located at 0.6 nm and 1.2 nm and high surface area. These robust micropores were confirmed by nitrogen sorption experiment and high-resolution transmission electron microscopy (TEM). Carbon dioxide, methane and hydrogen sorption experiments indicated that these novel porous carbon materials have significant gas sorption abilities in both low-pressure and high-pressure environments. Moreover the methane storage ability of K-PAF-1-750 is among the best at 35 bars, and its low-pressure gas adsorption abilities are also comparable to the best porous materials in the world. Combined with excellent physicochemical stability, these materials are very promising for industrial applications such as carbon dioxide capture and high-density clean energy storage.
Pub.: 14 Aug '13, Pinned: 29 Jun '17
Abstract: The molecular building block approach was employed effectively to construct a series of novel isoreticular, highly porous and stable, aluminum-based metal-organic frameworks with soc topology. From this platform, three compounds were experimentally isolated and fully characterized: namely, the parent Al-soc-MOF-1 and its naphthalene and anthracene analogues. Al-soc-MOF-1 exhibits outstanding gravimetric methane uptake (total and working capacity). It is shown experimentally, for the first time, that the Al-soc-MOF platform can address the challenging Department of Energy dual target of 0.5 g/g (gravimetric) and 264 cm(3) (STP)/cm(3) (volumetric) methane storage. Furthermore, Al-soc-MOF exhibited the highest total gravimetric and volumetric uptake for carbon dioxide and the utmost total and deliverable uptake for oxygen at relatively high pressures among all microporous MOFs. In order to correlate the MOF pore structure and functionality to the gas storage properties, to better understand the structure-property relationship, we performed a molecular simulation study and evaluated the methane storage performance of the Al-soc-MOF platform using diverse organic linkers. It was found that shortening the parent Al-soc-MOF-1 linker resulted in a noticeable enhancement in the working volumetric capacity at specific temperatures and pressures with amply conserved gravimetric uptake/working capacity. In contrast, further expansion of the organic linker (branches and/or core) led to isostructural Al-soc-MOFs with enhanced gravimetric uptake but noticeably lower volumetric capacity. The collective experimental and simulation studies indicated that the parent Al-soc-MOF-1 exhibits the best compromise between the volumetric and gravimetric total and working uptakes under a wide range of pressure and temperature conditions.
Pub.: 15 Sep '15, Pinned: 29 Jun '17
Abstract: Discoveries of novel functional materials have played very important roles to the development of science and technologies and thus to benefit our daily life. Among the diverse materials, metal–organic framework (MOF) materials are rapidly emerging as a unique type of porous and organic/inorganic hybrid materials which can be simply self-assembled from their corresponding inorganic metal ions/clusters with organic linkers, and can be straightforwardly characterized by various analytical methods. In terms of porosity, they are superior to other well-known porous materials such as zeolites and carbon materials; exhibiting extremely high porosity with surface area up to 7000 m2/g, tunable pore sizes, and metrics through the interplay of both organic and inorganic components with the pore sizes ranging from 3 to 100 Å, and lowest framework density down to 0.13 g/cm3. Such unique features have enabled metal–organic frameworks to exhibit great potentials for a broad range of applications in gas storage, gas separations, enantioselective separations, heterogeneous catalysis, chemical sensing and drug delivery. On the other hand, metal–organic frameworks can be also considered as organic/inorganic self-assembled hybrid materials, we can take advantages of the physical and chemical properties of both organic and inorganic components to develop their functional optical, photonic, and magnetic materials. Furthermore, the pores within MOFs can also be utilized to encapsulate a large number of different species of diverse functions, so a variety of functional MOF/composite materials can be readily synthesized.In this Account, we describe our recent research progress on pore and function engineering to develop functional MOF materials. We have been able to tune and optimize pore spaces, immobilize specific functional groups, and introduce chiral pore environments to target MOF materials for methane storage, light hydrocarbon separations, enantioselective recognitions, carbon dioxide capture, and separations. The intrinsic optical and photonic properties of metal ions and organic ligands, and guest molecules and/or ions can be collaboratively assembled and/or encapsulated into their frameworks, so we have realized a series of novel MOF materials as ratiometric luminescent thermometers, O2 sensors, white-light-emitting materials, nonlinear optical materials, two-photon pumped lasing materials, and two-photon responsive materials for 3D patterning and data storage.Thanks to the interplay of the dual functionalities of metal–organic frameworks (the inherent porosity, and the intrinsic physical and chemical properties of inorganic and organic building blocks and encapsulated guest species), our research efforts have led to the development of functional MOF materials beyond our initial imaginations.
Pub.: 15 Feb '16, Pinned: 29 Jun '17
Abstract: A metal organic framework (MOF) material including a Brunauer-Emmett-Teller (BET) surface area greater than 7,010 m2/g. Also a metal organic framework (MOF) material including hexa-carboxylated linkers including alkyne bond. Also a metal organic framework (MOF) material including three types of cuboctahedron cages fused to provide continuous channels. Also a method of making a metal organic framework (MOF) material including saponifying hexaester precursors having alkyne bonds to form a plurality of hexa-carboxylated linkers including alkyne bonds and performing a solvothermal reaction with the plurality of hexa-carboxylated linkers and one or more metal containing compounds to form the MOF material.
Pub.: 22 Dec '15, Pinned: 29 Jun '17
Abstract: Embodiments of the present disclosure provide for hydrophobic multi-component metal-organic materials (MOMs) (also referred to as “hydrophobic MOM”), systems that exhibit permanent porosity and using hydrophobic MOMs to separate components in a gas, methods of separating CO2 from a gas, and the like.
Pub.: 15 Nov '16, Pinned: 29 Jun '17
Abstract: This research note presents evidence that political polarization over the reality of human-caused climate change increases in tandem with individuals’ scores on a standard measure of actively open-minded thinking. This finding is at odds with the position that attributes political conflict over facts to a personality trait of closed-mindedness associated with political conservatism.
Pub.: 18 Nov '16, Pinned: 29 Jun '17
Abstract: Various scientific studies have investigated the causal link between solar activity (SS) and the earth’s temperature (GT). Results from literature indicate that both the detected structural breaks and existing trend have significant effects on the causality detection outcomes. In this paper, we make a contribution to this literature by evaluating and comparing seven trend extraction methods covering various aspects of trend extraction studies to date. In addition, we extend previous work by using Convergent Cross Mapping (CCM) - an advanced non-parametric causality detection technique to provide evidence on the effect of existing trend in global temperature on the causality detection outcome. This paper illustrates the use of a method to find the most reliable trend extraction approach for data preprocessing, as well as provides detailed analyses of the causality detection of each component by this approach to achieve a better understanding of the causal link between SS and GT. Furthermore, the corresponding CCM results indicate increasing significance of causal effect from SS to GT since 1880 to recent years, which provide solid evidences that may contribute on explaining the escalating global tendency of warming up recent decades.
Pub.: 27 Nov '16, Pinned: 29 Jun '17
Abstract: Global warming from carbon dioxide (CO2) is known to depend on cumulative CO2 emissions. We introduce a model of global expenditures on limiting cumulative CO2 emissions, taking into account effects of decarbonization and rising global income and making an approximation to the marginal abatement costs (MAC) of CO2. Discounted mitigation expenditures are shown to be a convex function of cumulative CO2 emissions. We also consider minimum-expenditure solutions for meeting cumulative emissions goals, using a regularized variational method yielding an initial value problem in the integrated decarbonization rate. A quasi-stationary solution to this problem can be obtained for a special case, yielding decarbonization rate that is proportional to annual CO2 emissions. Minimum-expenditure trajectories in scenarios where CO2 emissions decrease must begin with rapid decarbonization at rate decreasing with time. Due to the shape of global MAC the fraction of global income spent on CO2 mitigation ("burden") generally increases with time, as cheaper avenues for mitigation are exhausted. Therefore failure to rapidly decarbonize early on reduces expenditures by a small fraction (on the order of 0.01 %) of income in the present, but leads to much higher burden to future generations (on the order of 1 % of income).
Pub.: 12 Jun '17, Pinned: 29 Jun '17
Abstract: Depletion of fossil oil deposits and the escalating threat of global warming have put clean energy research, which includes the search for clean energy carriers such as hydrogen and methane as well as the reduction of carbon dioxide emissions, on the urgent agenda. A significant technical challenge has been recognized as the development of a viable method to efficiently trap hydrogen, methane and carbon dioxide gas molecules in a confined space for various applications. This issue can be addressed by employing highly porous materials as storage media, and porous metal-organic frameworks (MOFs) which have exceptionally high surface areas as well as chemically-tunable structures are playing an unusual role in this respect. In this feature article we provide an overview of the current status of clean energy applications of porous MOFs, including hydrogen storage, methane storage and carbon dioxide capture.
Pub.: 22 Dec '09, Pinned: 29 Jun '17
Abstract: Sustainable Technologies, Systems & Policies, Issue CCS Workshop, May 2012. The ability to rationally design materials for specific applications and synthesize materials to these exact specifications at the molecular level makes it possible to make a huge impact in carbon dioxide capture applications. Recently, advanced porous materials, in particular metal-organic frameworks (MOFs) and porous polymer networks (PPNs) have shown tremendous potential for this and related applications because they have high adsorption selectivities and record breaking gas uptake capacities. By appending chemical functional groups to the surface of these materials it is possible to tune gas molecule specific interactions. The results presented herein are a summary of the fundamentals of synthesizing several MOF and PPN series through applying structure property relationships.
Pub.: 21 Nov '12, Pinned: 29 Jun '17
Abstract: In the global transition to a sustainable low-carbon economy, CO2 capture and storage technology still plays a critical role for deep emission reduction, particularly for the stationary sources in power generation and industry. However, for small and mobile emission sources in transportation, CO2 capture is not suitable and it is more practical to use relatively clean energy, such as natural gas. In these two low-carbon energy technologies, designing highly selective sorbents is one of the key and most challenging steps. Toward this end, metal-organic frameworks (MOFs) have received continuously intensive attention in the past decades for their highly porous and diversified structures. In this review, the recent progress in developing MOFs for selective CO2 capture from post-combustion flue gas and CH4 storage for vehicle applications are summarized. For CO2 capture, several promising strategies being used to improve CO2 adsorption uptake at low pressures are highlighted and compared. In addition, the conventional and novel regeneration techniques for MOFs are also discussed. In the case of CH4 storage, the flexible and rigid MOFs, whose CH4 storage capacity is close to the target set by U.S. Department of Energy are particularly emphasized. Finally, the challenge of using MOFs for CH4 storage is discussed.
Pub.: 05 Dec '16, Pinned: 29 Jun '17
Abstract: Metal-organic frameworks are a class of crystalline porous materials with potential applications in catalysis, gas separation and storage, and so on. Of great importance is the development of innovative synthetic strategies to optimize porosity, composition and functionality to target specific applications. Here we show a platform for the development of metal-organic materials and control of their gas sorption properties. This platform can accommodate a large variety of organic ligands and homo- or hetero-metallic clusters, which allows for extraordinary tunability in gas sorption properties. Even without any strong binding sites, most members of this platform exhibit high gas uptake capacity. The high capacity is accomplished with an isosteric heat of adsorption as low as 20 kJ mol(-1) for carbon dioxide, which could bring a distinct economic advantage because of the significantly reduced energy consumption for activation and regeneration of adsorbents.
Pub.: 08 Dec '16, Pinned: 29 Jun '17
Abstract: Metal-organic framework (MOF) materials have emerged as one of the favorite crystalline porous materials (CPM) because of their compositional and geometric tunability and many possible applications. In efforts to develop better MOFs for gas storage and separation, a number of strategies including creation of open metal sites and implantation of Lewis base sites have been used to tune host-guest interactions. In addition to these chemical factors, the geometric features such as pore size and shape, surface area, and pore volume also play important roles in sorption energetics and uptake capacity. For efficient capture of small gas molecules such as carbon dioxide under ambient conditions, large surface area or high pore volume are often not needed. Instead, maximizing host-guest interactions or the density of binding sites by encaging gas molecules in snug pockets of pore space can be a fruitful approach. To put this concept into practice, the pore space partition (PSP) concept has been proposed and has achieved a great experimental success. In this account, we will highlight many efforts to implement PSP in MOFs and impact of PSP on gas uptake performance. In the synthetic design of PSP, it is helpful to distinguish between factors that contribute to the framework formation and factors that serve the purpose of PSP. Because of the need for complementary structural roles, the synthesis of MOFs with PSP often involves multicomponent systems including mixed ligands, mixed inorganic nodes, or both. It is possible to accomplish both framework formation and PSP with a single type of polyfunctional ligands that use some functional groups (called framework-forming group) for framework formation and the remaining functional groups (called pore-partition group) for PSP. Alternatively, framework formation and PSP can be shouldered by different chemical species. For example, in a mixed-ligand system, one ligand (called framework-forming agent) can play the role of the framework formation while the other type of ligand (called pore-partition agent) can assume the role of PSP. PSP is sensitive to the types of inorganic secondary building units (SBUs). The coexistence of SBUs complementary in charge, connectivity, and so on can promote PSP. The use of heterometallic systems can promote the diversity of SBUs coexistent under a given condition. Heterometallic system with metal ions of different oxidation states also provides the charge tunability of SBUs and the overall framework, providing an additional level of control in self-assembly and ultimately in the materials' properties. Of particular interest is the PSP in MIL-88 type (acs-type topology) structure, which has led to a huge family of CPMs (called pacs CPMs, pacs = partitioned acs) exhibiting low isosteric heat of adsorption and yet superior CO2 uptake capacity.
Pub.: 21 Jan '17, Pinned: 29 Jun '17
Abstract: The influence of the metal (M) coordinated by the salen ligand in DUT-117(M) compounds (M − Cu, Ni, Pd) on the gas adsorption capacity for hydrogen (77 K), methane (298 K), and carbon dioxide (298 K) was investigated.The metal–organic framework (MOF) Cu4(mpbatb)2 (mpbatb-4,4′,4″,4‴-(1,3-phenylenebis(azanetriyl))tetrabenzoate), also known as DUT-71 (DUT – Dresden University of Technology), was functionalized via postsynthetic cross-linking of the copper paddle wheels by linear salen derivatives and dabco (1,4-diazabicyclo[2.2.2]octane). This results in a series of porous MOFs, denoted as DUT-117(M) (M – Cu, Ni, Pd). Besides significant improvement of the framework robustness, the influence of the metal coordinated by the salen ligand on the gas adsorption capacity (hydrogen –196 °C, methane 25 °C, and carbon dioxide 25 °C) was investigated. In this series DUT-117(Ni) stands out as the best material for adsorptive methane storage with a high working capacity of 171 cm3·cm–3 between 5 and 65 bar.
Pub.: 17 Apr '17, Pinned: 29 Jun '17