Qingli Qian

Porous Silicon Carbide/Carbon Composite Microspherules for Methane Storage

Abstract Porous silicon carbide/carbon (SiC/C) microspherules were prepared by the controlled heating treatment of polymer and silica hybrid precursors over 1000 °C in Ar/H 2 stream. The resultant SiC/C composite shows improved physical properties such as excellent mechanical strength, regular physical form, and high packing density. Such improvement overcomes the main inherent problems encountered when using activated carbons as absorbents without sacrificing porosity properties. N 2 sorption analysis shows that the SiC/C composite has a BET surface area of 1793 m 2 /g and a pore volume of 0.92 ml/g. Methane adsorption isotherm is determined by the conventional volumetric method at 25 °C andupto7.0MPa. On volumetric basis, the SiC/C composite microspherules show methane storage of 145 (V/V) at 3.5 MPa and 25 °C. The combination of excellent physical properties and porosity properties in this SiC/C composite lends a great possibility to develop a competitive storage system for natural gas.

Direct removal of trace ionic iodide from acetic acid via porous carbon spheres.

The main purpose of this paper is to report the direct removal of trace ionic iodide (I(-)) from acetic acid through porous carbon spheres (PCS) derived from the carbonization of poly(vinylidene chloride). The surface morphology and pore size distribution of the PCS are distinct from activated carbon (AC); thus they possess the peculiar performance of removing ionic iodide from acetic acid. The easy reach of micropores in the PCS was different from that of AC, but similar to that of activated carbon fiber (ACF). The iodide removal process has a strong relation with temperature, which is a typical feature of physical adsorption. The ionic iodide content in acetic acid used in the adsorption experiment was at the parts per billion level, and the factors influencing the adsorption are discussed in detail.

Vinyl acetate formation in the reaction of acetylene with acetic acid catalyzed by zinc acetate supported on porous carbon spheres

A kind of porous carbon spheres (PCS) was prepared by the carbonization of poly(vinylidene chloride) synthesized by suspension polymerization. Structure analyses revealed the existence of bumps and holes on the surface of PCS. The PCS, with the pore size between 0.8–1.2 nm, could be used as the support of zinc acetate because of the regular shape, high specific surface area, and good mechanical strength. Vinyl acetate was produced from acetylene and acetic acid using the PCS-supported zinc acetate (PCS-Zn) under mild conditions. In a single-pass operation performed at 220°C, the conversions of acetic acid and acetylene reached 22.6 and 5.3% respectively while the activity of vinyl acetate formation was above 1000 g mol−1 h−1.

Supported Ag nanoparticles as trace iodide adsorbent from acetic acid

Ag nanoparticles (AgNPs) were used as adsorbent to remove trace iodide from acetic acid. Under identical conditions, AgNPs adsorbent with 0.5 wt % Ag has the same performance as commercial adsorbent with 10 wt % Ag+. In addition, Ag loss of AgNPs adsorbent is remarkably lower than that of commercial adsorbent. The Ag content in AgNPs adsorbent affects its adsorption performance, and the optimal content is 1.0 wt %. Saturated AgNPs adsorbent can be regenerated by hydrogen reduction and reused with satisfying performance. The properties of AgNPs adsorbent are based on surface effect of nanoparticles, differing from commercial Ag+ type adsorbents. In a word, AgNPs adsorbent is of high efficiency, low Ag loss and easy recycling, thus making it “green adsorbent” for removing iodide from acetic acid.