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The H 2 S removal capacity of copper loaded on a number of titanosilicate supports was investigated. Copper supported on Engelhard Titanosilicate-2 (Cu-ETS-2) has been found to be a superior H 2 S scavenger for maintaining H 2 S levels below 0.5 ppm because of its high cation exchange capacity and copper dispersion. Cu-ETS-2 demonstrated higher utilization at room temperature when compared to fully developed commercial H 2 S adsorbents. In addition it was found that the adsorption capacity of Cu-ETS-2 is maintained over a wide range of activation temperatures.

Al2O3 and its supported metal catalysts are widely used in deNO x catalysis, but the true nature of the catalytic sites and the structure−activity relationships are still unclear. By a set of systematic and comparative calculations, this study investigates the adsorption of NO and NO2, and nitrate formation via the oxidation of NO on Al2O3 and Ga modified Al2O3 surfaces using density functional theory. It is found that NO x gases (NO and NO2) preferentially adsorb on (110) planes, and are oriented in different configurations. While NO bonds with the (110) surfaces through an N-down orientation, the most stable mode of adsorption of NO2 on the (110) surfaces is a bidentate configuration, causing much higher net charge transfer from the surface and noticeable elongation of the N−O bond. Both the NO and NO2 adsorption and activation are promoted on the Ga modified Al2O3 (110) surface. Moreover, the activation energy barrier for nitrate formation via NO oxidation, a process crucial for the selective catalytic reduction of NO x , is about 35% less on the Ga modified Al2O3 (110) surface compared to the pristine Al2O3 (110) surface. This is one of the reasons for the high activity of Ga2O3−Al2O3 catalyst for the selective catalytic reduction of NO x .

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