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. </span

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 &nbsp;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 CO₂</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