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In an effort to develop selective solid sorbents for acidic gas (CO 2 and H 2 S) removal from natural gas mixtures, we synthesized amine-surface-modified silica xerogel and MCM-48 materials. With large amounts of basic amine groups on the surface, the sorbents are able to selectively bind the acidic gases CO 2 and H 2 S. High adsorption capacities and adsorption rates were obtained for both gases. The adsorption-desorption isotherms of the gases and thermogravimetric analysis of the sorbents showed that these sorbents can be regenerated completely under mild conditions such as those used in pressure swing or temperature swing adsorption processes. We have also investigated the effect of moisture on the adsorption of CO 2 and H 2 S by TPD-MS and infrared spectroscopy. The results indicated that the presence of water vapor doubled the amount of CO 2 adsorbed and barely affected the H 2 S adsorption.

Deep desulfurization of transportation fuels (gasoline, diesel, and jet fuels) is being mandated by U.S. and foreign governments and is also needed for future fuel cell applications. However, it is extremely difficult and costly to achieve with current technology, which requires catalytic reactors operated at high pressure and temperature. We show that Cu+ and Ag+ zeolite Y can adsorb sulfur compounds from commercial fuels selectively and with high sulfur capacities (by pi complexation) at ambient temperature and pressure. Thus, the sulfur content was reduced from 430 to <0.2 parts per million by weight in a commercial diesel at a sorbent capacity of 34 cubic centimeters of clean diesel produced per gram of sorbent. This sulfur selectivity and capacity are orders of magnitude higher than those obtained by previously known sorbents.

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The possible utilization of hydrogen as the energy source for fuel-cell vehicles is limited by the lack of a viable hydrogen storage system. Metal-organic frameworks (MOFs) belong to a new class of microporous materials that have recently been shown to be potential candidates for hydrogen storage; however, no significant hydrogen storage capacity has been achieved in MOFs at ambient temperature. Here we report substantially increased hydrogen storage capacities of modified MOFs by using a simple technique that causes and facilitates hydrogen spillover. Thus, the storage of 4 wt % is achieved at room temperature and 100 atm for the modified IRMOF-8. The adsorption is reversible, and the rates are fast. That has made MOFs truly promising for hydrogen storage application.

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