To capture elemental mercury (Hg 0 ) at high temperatures in simulated syngas, Pd/Al 2 O 3 sorbents were developed using an impregnation method. The Pd/Al 2 O 3 sorbents with a Pd loading value of 8% exhibited high Hg 0 capture activity from 200 to 270 °C. Over 90% of the mercury capture by 8Pd/Al 2 O 3 was achieved for operating temperatures up to 270 °C. The superior performance of Pd/Al 2 O 3 sorbents could be primarily ascribed to the formation of a Pd−Hg amalgam. H 2 and CO were found to be promotional on Hg 0 capture because of the reduction of PdO to Pd metal. H 2 S significantly inhibited Hg 0 capture due to the consumption of the active palladium. HCl promoted Hg 0 capture, which could be ascribed to the catalytic oxidation of Hg 0 to HgCl 2 . H 2 O showed a prohibitive effect on Hg 0 removal. The regeneration experiments indicated that the spent Pd/Al 2 O 3 sorbents could be facilely revivified and reused.

Mandarin (Citrus reticulata), a non-climacteric fruit, is an economically important fruit worldwide. The mechanism underlying senescence of non-climacteric fruit is poorly understood. In this study, a gel-based proteomic study followed by LC-ESI-MS/MS analysis was carried out to investigate the proteomic changes involved in peel senescence in harvested mandarin “Shatangju” fruit stored for 18 days. Over the course of the storage period, the fruit gradually senesced, accompanied by a decreased respiration rate and increased chlorophyll degradation and disruption of membrane integrity. Sixty-three proteins spots that showed significant differences in abundance were identified. The up-regulated proteins were mainly associated with cell wall degradation, lipid degradation, protein degradation, senescence-related transcription factors, and transcription-related proteins. In contrast, most proteins associated with ATP synthesis and scavenging of reactive oxygen species were significantly down-regulated during peel senescence. Three thioredoxin proteins and three Ca2+ signaling-related proteins were significantly up-regulated during peel senescence. It is suggested that mandarin peel senescence is associated with energy supply efficiency, decreased antioxidant capability, and increased protein and lipid degradation. In addition, activation of Ca2+ signaling and transcription factors might be involved in cell wall degradation and primary or secondary metabolism.

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CeO2 was doped into Pd/Al2O3 using an impregnation method to suppress the interference of H2S and to improve the ability to capture elemental mercury (Hg0) from syngas at high temperatures. As a result, the Hg0 capture performance was generally enhanced by the incorporation of Ce as a result of the consumption of H2S. The individual presence of H2 or CO resulted in the formation of Pd metal responsible for Hg0 capture and active ceria in reduced form for H2S removal, thus promoting the Hg0 removal. Meanwhile, H2S could react with CO to form COS, which competed with Hg0 for active sites, hence inhibiting Hg0 capture. The effect of HCl on Hg0 capture over PCA sorbents was found to be slightly promotional, because a small amount of Hg0 was oxidized to HgCl2. More importantly, the spent PCA sorbents could be easily reactivated, indicating that this material is a prospective candidate for Hg0 control from syngas.