Huli Yu,Liangjie Wang,Sheng Liu,Biao Zhao,Ke Xiao,Bo Yang,Huabo Duan,Huazhang Zhao,Jianping Deng
Poly/oligosaccharides are renewable natural resources with abundant chirality . Herein, we develop a general route to prepare optically active particles by using poly/oligosaccharides as both chiral inducers and growth templates. By complexing with Cu(NH 3 ) 4 2+ ions, OH groups on C2 and C3 in poly/oligosaccharides can transfer the chirality to Cu(II) and retain it in CuO . At the same time, poly/oligosaccharides direct growth of CuO by in situ transformation of Cu(NH 3 ) 4 2+ ions. Cellulose nanocrystal (CNC) and starch (ST) are used as representative polysaccharides , and β-cyclodextrin (β-CD) as a representative oligosaccharide, thus dandelion , duchesnea, and chrysanthemum-like composite particles with chiroptical activity are obtained. Besides, chiral CuO/poly(oligo)saccharide particles (CSP) demonstrate enantioselective ability by differentiating coordination with tryptophan (Trp) enantiomers and form Cu-Trp metal organic framework architectures with different morphologies. The study provides an easily accessible approach to prepare novel functional materials by poly/oligosaccharide-based chiral induction and hold great promise in chiral applications.
Jianping Yang,Xingyue Zhou,Wei Zheng,Penglin Zhu,Fanyue Meng,Zequn Yang,Wenqi Qu,Hailong Li
Efficiently removing elemental mercury (Hg 0 ) from natural gas is a serious task to both equipment safety and ecosystem. The granulation of adsorbent powder is required to reduce pressure loss and adsorbent elutriation from a fixed-bed demercuration system. Herein, urea modified CuO (Urea/CuO) pellets were developed for Hg 0 adsorption from natural gas with H 2 S. The characterization results show that the addition of urea accelerated the formation of pore structure and surface oxygen, thus enhancing the Hg 0 adsorption performance of CuO pellets. The Urea/CuO pellets with 20 % urea additive amount exhibited 93 % Hg 0 removal efficiency under the existence of 500 ppm H 2 S and a gaseous hourly space velocity of 1.21 × 10 5 h −1 . H 2 S was essential to in-situ convert Urea/CuO pellets into a highly active Hg 0 adsorbent. With the increase of H 2 S concentration from 0 to 1000 ppm, the Hg 0 removal efficiency was raised from 34 % to 93 %. Urea/CuO pellets performed well for Hg 0 adsorption at 10–50 °C, which was the representative temperature window of natural gas processing. The Hg 0 adsorption capacity and uptake rate of Urea/CuO with 500 ppm H 2 S reached as high as 27.06 mg·g −1 and 2.44 μg·g −1 ·min −1 , which largely exceeded those of commercial activated carbons specialized for Hg 0 adsorption as well as typical granulated Hg 0 adsorbents reported in previous literature. The existence of H 2 S in natural gas in-situ converted CuO into CuS. The S 2 2− on the formed CuS could act as active sites for Hg 0 adsorption, in which gaseous Hg 0 was captured as stable mercury sulfide (HgS). The deactivated adsorbent could be regenerated and reused by thermally decomposing HgS and replenishing the consumed surface oxygen and the sintering surface. With these advantages, the developed Urea/CuO pellets appears to be a promising Hg 0 adsorbent from natural gas with H 2 S.
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