U.S. undergraduate students may select from amongst the following projects offered by the National University of Singapore for the 2015 summer ACS IREU:
||Developing portable water purification devices||Prof. Suresh VALIYAVEETTIL|
||Synthesis of Water-Stable UiO-66 MOFs for Carbon Dioxide Conversion to Cyclic Carbonates||Dr. Zhao Dan|
Metal/Metal Oxide-MOF Hybrid Structure for Electrochemical Application
|Dr. ZHAO Dan|
*Please note, there is no NUS.1 project code.
Availability of potable water is a serious issue in many parts of the world. This is also a reason for the spread of diseases in local population. Many technologies are available for water purification, but they are usually expensive and not affordable to poor countries. The project involves the design and fabrication of simple devices which could be used for the removal of pollutants. The students will do a literature search first and choose appropriate materials for the device. They will also demonstrate the efficiency of the devices under laboratory conditions.
Carbon dioxide has been gaining ever-increasing attention because of its greenhouse effect which could incur global warming, species extinction and human nutrition deficiency. Although more and more researchers nowadays are developing new technologies to do CO2 capture and separation, it is still a temporary solution since how to deal with large amount of captured CO2 remains a big challenge. In the long term, the utilization of CO2 as a raw material in the production of commercially important chemicals provides another promising alternative in reducing atmospheric CO2 concentration and producing renewable feedstock for chemical industry. Metal-organic frameworks (MOFs), are a new class of crystalline hybrid materials composed of organic linkers and metal ions, have recently emerged as an ideal platform for engineering novel functional porous materials. Because of possessing the diversity of coordinated models of metal ions and functional organic linkers, MOFs can surely fill a niche in the search of porous materials for catalytic CO2 conversion. This project deals with synthesizing water-stable UiO-66 MOFs as heterogeneous catalysis for catalytic CO2 conversion. It is hoped to develop functional UiO-66 MOFs of highly exposed Lewis sites and high BET surface area for highly effective CO2 conversion to cyclic carbonates, with easy regeneration and low costs.
The large-scale anthropogenic CO2 emission has aroused world-wild concerns nowadays. Ample evidence has shown that the escalating atmospheric CO2concentration is the reason for global warming and ocean acidification. The impact of these climate changes on our environment and society could be enormous and irreversible if prompt actions are not taken. The development of applicable carbon mitigation techniques will not only have academic interests, but also bring economical and social benefits. One of the key steps in carbon mitigation is CO2 capture from those stationary CO2 emission resources. The adsorption-based CO2 capture using pressure/temperature swing sorption technique has the advantages of lower cost and easier regeneration of the adsorbents, thus receiving a lot of attention recently. The ideal adsorbents for CO2 capture should have the properties of high adsorption capacity for CO2, high selectivity for CO2, fast sorption kinetics, strong mechanical strength, high chemical stability to impurities (water, SOx, NOx, etc.), easy regeneration, and low costs. Unfortunately no adsorbent available nowadays can meet all of the above criteria. Metal-organic frameworks (MOFs), which represent a new frontier for material research, are coordination polymers consisting of metal ions/clusters as nodes and organic ligands as spacers. Possessing the merits of both inorganic and organic building units, MOFs can fill a niche in the search for new porous materials and have found wide applications in gas storage, adsorption-based gas/vapor separation, shape/size-selective catalysis, and as templates/precursors in the preparation of other porous materials. The study of using MOFs for CO2 capture is booming due to their high surface area (the current record holder is MOF-210, with a Langmuir surface area of 10400 m2/g), uniform yet tunable pore size/geometry, and strong interaction with CO2via coordinatively unsaturated metal centers and/or functionalized organic ligands. However, most of the MOFs reported so far have poor hydrothermal stability, which greatly limits their application in industrial CO2 capture. A novel zirconium MOF (UiO-66) was reported in 2008. Because of the strong Zr-O bond, this MOF exhibited superior hydrothermal and chemical stability, which made it a promising candidate for industrial CO2 capture. In this project, we propose to synthesize several Zr MOFs using alkylamine-containing ligands. It is hoped that the Zr-O building units will offer good solvothermal and chemical stability in these MOFs, with alkylamine groups having strong CO2interactions to increase both the capacity and selectivity of CO2 uptake.