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Recent publications on zeolites and catalysis
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Recent Publications on Zeolites and Catalysis A number of papers have appeared recently that will be of interest to Newsbrief readers as they describe new approaches concerning zeolites and zeotypes. The synthesis of Co doped VPI-5 has been described and it is demonstrated that the material has bi-functional catalytic activity for isopropyl alcohol conversion [P.S. Singh et al., J. Chem. Soc., Chem. Commun., (1995) 2255]. TS-1 continues to be studied as it is an extremely efficient oxidation catalyst. Recently G. Zhang et al. [J. Chem. Soc., Chem. Commun., (1995) 2259] have described the preparation of discrete colloidal crystals of TS-1 which have an average ultimate-crystallite size of 100 nm and are prepared in ethanol. Low temperature CO oxidation is becoming an important reaction and V. Junges et al. have used MCM-41 supported small Pt particles as a catalyst for this reaction [J. Chem. Soc., Chem. Commun., (1995) 2283]. These catalysts are shown to be active in the temperature range from ambient up to 120°C with the best performance being achieved with small Pt particles of ca. 2 nm in size. The room temperature synthesis of a highly active vanadium-containing mesoporous molecular sieve, V-HMS has been described [J.S. Reddy and A. Sayari, J. Chem. Soc., Chem. Commun., (1995) 2231]. The material has a pore size of ca. 40 ,& and is thermally stable. Its use as an oxidation catalyst for the conversion of 2,6di-tert-butyl phenol using either hydrogen peroxide or tert butyl hydroperoxide as oxidant is described and very high selectivity to quinone is reported (92-100%) with
applied catalysis A: General
H202 efficiencies of up to 95% being observed. For those researchers attempting to synthesise aluminium free Fi-B, an X-ray spectroscopy study of this material has just been published by R.J. Davis et al. [Catal. Lett., 34 (1995) 101-113]. The material was obtained from ARCO and was synthesised according to their patent method [US patent appl. #08/329732]. Graham J. Hutchings
Recent Publications Concerning Enantioselective Catalysis
One of the most studied reactions in this area is the hydrogenation of ethyl pyruvate using chirally modified Pt catalysts. This reaction has now been investigated in supercritical fluids [B. Minder, T. Mallet, K.H. Pickel, K. Steiner and A. Balker, Catal. Lett., 34 (1995) 1-9]. They studied the enantioselective hydrogenation of ethyl pyruvate to (R)-ethyllactate using gases under supercritical conditions as solvents with a 5% Pt catalyst modified with cinchonidine. In supercritical ethane, the reaction time was decreased by a factor of 3-5, compared to toluene as solvent under similar conditions, without any loss of enantioselectivity. Supercritical CO2 was observed to give catalyst deactivation due to the reduction of CO2 on the Pt. A chirally layered aluminophosphate Co(tn)3AI3P4Ol~.2H20 containing only one enantiomer of the metal complex has been synthesised using racemic Co(tn)3CI3 as templating agent and its structure has been reported using single crystal XRD [D.A. Bruce et al., J. Chem. Soc., Chem. Commun., (1995) 2059]. Tlqis Volume 143 No. 2 -
28 August 1996
Recent Publications on Zeolites and Catalysis A number of papers have appeared recently that will be of interest to Newsbrief readers as they describe new approaches concerning zeolites and zeotypes. The synthesis of Co doped VPI-5 has been described and it is demonstrated that the material has bi-functional catalytic activity for isopropyl alcohol conversion [P.S. Singh et al., J. Chem. Soc., Chem. Commun., (1995) 2255]. TS-1 continues to be studied as it is an extremely efficient oxidation catalyst. Recently G. Zhang et al. [J. Chem. Soc., Chem. Commun., (1995) 2259] have described the preparation of discrete colloidal crystals of TS-1 which have an average ultimate-crystallite size of 100 nm and are prepared in ethanol. Low temperature CO oxidation is becoming an important reaction and V. Junges et al. have used MCM-41 supported small Pt particles as a catalyst for this reaction [J. Chem. Soc., Chem. Commun., (1995) 2283]. These catalysts are shown to be active in the temperature range from ambient up to 120°C with the best performance being achieved with small Pt particles of ca. 2 nm in size. The room temperature synthesis of a highly active vanadium-containing mesoporous molecular sieve, V-HMS has been described [J.S. Reddy and A. Sayari, J. Chem. Soc., Chem. Commun., (1995) 2231]. The material has a pore size of ca. 40 ,& and is thermally stable. Its use as an oxidation catalyst for the conversion of 2,6di-tert-butyl phenol using either hydrogen peroxide or tert butyl hydroperoxide as oxidant is described and very high selectivity to quinone is reported (92-100%) with
applied catalysis A: General
H202 efficiencies of up to 95% being observed. For those researchers attempting to synthesise aluminium free Fi-B, an X-ray spectroscopy study of this material has just been published by R.J. Davis et al. [Catal. Lett., 34 (1995) 101-113]. The material was obtained from ARCO and was synthesised according to their patent method [US patent appl. #08/329732]. Graham J. Hutchings
Recent Publications Concerning Enantioselective Catalysis
One of the most studied reactions in this area is the hydrogenation of ethyl pyruvate using chirally modified Pt catalysts. This reaction has now been investigated in supercritical fluids [B. Minder, T. Mallet, K.H. Pickel, K. Steiner and A. Balker, Catal. Lett., 34 (1995) 1-9]. They studied the enantioselective hydrogenation of ethyl pyruvate to (R)-ethyllactate using gases under supercritical conditions as solvents with a 5% Pt catalyst modified with cinchonidine. In supercritical ethane, the reaction time was decreased by a factor of 3-5, compared to toluene as solvent under similar conditions, without any loss of enantioselectivity. Supercritical CO2 was observed to give catalyst deactivation due to the reduction of CO2 on the Pt. A chirally layered aluminophosphate Co(tn)3AI3P4Ol~.2H20 containing only one enantiomer of the metal complex has been synthesised using racemic Co(tn)3CI3 as templating agent and its structure has been reported using single crystal XRD [D.A. Bruce et al., J. Chem. Soc., Chem. Commun., (1995) 2059]. Tlqis Volume 143 No. 2 -
28 August 1996