http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hee Jong Lee,김화용,Doyoung Seung,Igor N. Filimonov 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.3
Etherification of glycerol by isobutylene was performed using ion-exchange resin Amberlyst 15, partially neutralized Amberlyst 15 as heterogeneous catalyst, and p-toluenesulfonic acid as a homogeneous catalyst. Amberlyst 15 exhibited strong internal diffusion limitations for the initial composition of reaction mixture. Diffusion limitations decrease in the course of reaction due to the accumulation of mono-ether having excellent solubilizing properties. Oligomerized isobutylene is a dominant by-product for high isobutylene-to-glycerol ratio and long contact time in the case of Amberlyst 15. Density reduction of acidic protons in Amberlyst 15 by partial ion exchange with sodium ions leads to considerable reduction of isobutylene affinity to Amberlyst 15, and as a result, it reduced losses of isobutylene. This partial neutralization leads to lower space-time yields of target products, but enhances selectivity to higher ethers with maintaining conversion of glycerol over 95%.
2,3-Butanediol dehydration catalyzed by silica-supported sodium phosphates
Kim, W.,Shin, W.,Lee, K.J.,Song, H.,Kim, H.S.,Seung, D.,Filimonov, I.N. Elsevier 2016 Applied Catalysis A Vol.511 No.-
<P>Catalytic gas phase dehydration of 2,3 butanediol (BDO) was studied in the fixed bed reactor over silica-supported sodium phosphates for a wide range of Na/P ratios (Na/P = 0-3) and variable content of phosphates. Major products were 1,3-butadiene (BD) and methyl ethyl ketone (MEK) for long contact times. 3-Buten-2-ol (3B2OL) and MEK are major products for the short contact times. Achieved yields of elimination products (BD + 3B2OL) were over 60% per pass at Na/P = 1.8-1.9 which is the optimum combination of acidic and basic components for the long term production of BD or 3B2OL from BDO. Minor products detected at short contact times (2,3-epoxybutane, 2,3-butanedione and acetoin) imply that hydrogen transfer and dehydrative epoxidation are minor pathways. Mass transport limitations are more apparent for BDO -> 3B2OL -> BD route (elimination) than for BDO MEK route (rearrangement). This leads to the lower selectivity of elimination products at long contact time and/or insufficient flow rate of the carrier gas. 2-butanol dehydration using the same catalysts shows considerable selectivity to 1-butene (1-BT) providing evidence for Eta elimination mechanism that requires concerted action of acid-base pairs. NH3 and CO2 TPD studies confirmed existence of weak acid and basic sites for the sodium phosphates supported on silica. High affinity adsorption of pyridine (Py) and benzoic acid (BA) shows maximum of acid/base ratio at Na/P similar to 1.5-2. According to XRD and P-31 MAS NMR data the catalysts providing the best performance are composed of pyrophosphates and tripolyphosphates finely dispersed on the surface of silica. XPS shows considerable migration of surface sodium cations into the bulk when Na/P ratio exceeds 1.4. (C) 2015 Elsevier B.V. All rights reserved.</P>
Lattice dynamics and antiferroelectricity inPbZrO3tested by x-ray and Brillouin light scattering
Burkovsky, R. G.,Tagantsev, A. K.,Vaideeswaran, K.,Setter, N.,Vakhrushev, S. B.,Filimonov, A. V.,Shaganov, A.,Andronikova, D.,Rudskoy, A. I.,Baron, A. Q. R.,Uchiyama, H.,Chernyshov, D.,Ujma, Z.,Rolede American Physical Society 2014 Physical review. B, Condensed matter and materials Vol.90 No.14