32 research outputs found
Vapor phase chemoselective conjugate hydrogenation of isophorone over Pd/SBA-15 catalysts
557-560A series of
Pd/SBA-15 catalysts with 1, 2, 3, 4% (by weight) Pd loading has been prepared
by a conventional impregnation method and characterized by N2-sorption,
low-angle and wide-angle XRD, XPS and TEM techniques. These catalysts exhibit
excellent activities for chemoselective hydrogenation of isophorone to
dihydroisophorone showing 100% conversion and 100% selectivity in gas phase at
atmospheric pressure. The structural and textural characteristics of the
catalysts play a crucial role in exhibiting high conversion and selectivity
Triflamide anchored SBA-15 catalyst for nitration of alkyl aromatics in microwave
545-549A series of triflamide anchored SBA-15
(SBA-NH-TA) catalysts with 5-20 wt% triflic acid (TA) loadings have been
synthesized through the functionalization of propylamine on the surface of
SBA-15 (SBA-NH2), followed by covalent attachment of triflic acid
with –NH2 group of SBA-NH2. With SBA-NH-TA as catalyst
and 69% HNO3 as nitrating agent, highly accelerated and safe
nitration of aromatic compounds in microwave under solvent-free conditions has
been achieved. The structural and textural characteristics of SBA-NH-TA
catalysts have been determined from N2
sorption and low-angle XRD techniques. As the loading of TA increases, the
conversion of alkylaromatics to their nitrated products increases
significantly. Reaction parameters like amount of catalyst, amount of
triflic acid loading, substrate to nitric acid ratio, reaction temperature and
reaction time have been investigated.
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Catalytic dehydration of 1-phenylethanol over chromia-carbon composite derived from metal organic framework, CrMIL-101
572-575The synthesis and characterization of a new
composite material containing chromia and carbon using metal organic framework
(Cr-MIL-101) is presented. The dispersion of chromia particles on carbon
material by direct thermal treatment of Cr-MIL-101 containing terephthalate is
also described. The investigation of removal of guest molecules in Cr-MIL-101
leading to the formation of chromia in the temperature range of 373-473 K has
been studied. The catalytic activity of the composite material for dehydration
of 1-phenylethanol is tested as a possible application. The composite catalytic
system can be used up to 10 h without
significant loss of activity
Unique Lewis and Bronsted acidic sites texture in the selective production of tetrahydropyran and oxepanefrom1,5-pentanediol and 1,6-hexanediol over sustainable red brick clay catalyst
Activated red brick (ARB) clay material proved superb catalyst for selective conversion of 1,5-pentanediol (1,5-PDO) to tetrahydropyran (THP) and 1,6-hexanediol (1,6-HDO) to oxepane (OP) via dehydration under vapor phase conditions in a continuous flow reactor. As per scanning electron microscopy (SEM), SEM-EDX and X-ray fluorescence (XRF) techniques, ARB clay catalyst majorly possessed silica (quartz), and iron oxide (hematite) species, and synergistic texture contributed to the catalytic efficiency for prolonged time-on-stream (TOS). The combination of active Lewis and Bronsted acidic sites with weak to mild acidic nature in the ARB clay obviously facilitates the dehydration reaction with high selectivity, tetrahydropyran (82%) and oxepane (89%). ARB clay displayed superior catalytic properties in the dehydration of alcohols compared with activities of commercial silica and α-Fe2O3 as catalysts. Commercial silica and α-Fe2O3 catalysts possessing the Lewis acidic sites only did not facilitate synchronous dehydration mechanism
<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB">Molybdenum oxide supported on COK-12: A novel catalyst for oxidative dehydrogenation of ethylbenzene using CO<sub>2</sub></span>
493-498P6m-type mesoporous silica
(COK-12) prepared at quasi-neutral pH in a buffered medium using sodium
silicate as a silica source has been used as a support to prepare a series of
MoO3/COK-12 catalysts with variable MoO3 loadings by wet
impregnation technique. Among these catalysts, 14 wt% MoO3/COK-12
with small particle size of MoO3 shows superior activity for the
oxidative dehydrogenation of ethylbenzene to styrene in the presence CO2