ChemInform Abstract: Acidity and Catalytic Activity of Zirconium and Titanium Sulfates Heat-Treated at High Temperature. Solid Superacid Catalysts.

ChemInform ◽  
1990 ◽  
Vol 21 (18) ◽  
Author(s):  
K. ARATA ◽  
M. HINO ◽  
N. YAMAGATA
1991 ◽  
Vol 56 (7) ◽  
pp. 1417-1426
Author(s):  
Tomáš Hochmann ◽  
Karel Setínek

Acid properties of the oxides Al2O3, SiO2, TiO2, SnO2, Sb2O3, ZrO2 and ZrSiO4 were modified by the action of Lewis acids. The acids ( AlCl3, TiCl4, PCl5, SbF5 and P2O5) were deposited on the oxides by sublimation at 150, 250 and 350°C. The strength and number of acid centres of the prepared catalysts and their catalytic activity in hydrocarbon reactions were determined.


1998 ◽  
Vol 25 (2) ◽  
pp. 173 ◽  
Author(s):  
M. A. B. Wallwork ◽  
S. J. Logue ◽  
L. C. MacLeod ◽  
C. F. Jenner

Plants of malting barley variety Schooner were exposed to 5 days of high temperatures (up to 35°C) during mid grain filling under controlled environment conditions. Grains from heat treated plants accumulated c. 30% less starch than grains from control plants (21/16°C; 14 h day). Reduced starch deposition was not limited by assimilate levels in heat treated grains, but high temperature reduced the conversion of sucrose to starch. The reduction in starch synthesis appeared to result from the effects of diminished catalytic activity of a number of enzymes in the committed pathway of starch synthesis, and/or delayed recovery of enzyme activity in the cooler recovery conditions. Reductions of 11–75% in the activity of the enzymes under investigation followed high temperature exposure. In addition, ADPglucose pyrophosphorylase, branching enzyme and granule bound starch synthase showed increased activity during exposure to moderate temperatures (28–32°C), but reduced activity at high temperatures, while soluble starch synthase showed an immediate loss of activity, even at moderate temperatures. Sucrose synthase and UDPglucose pyrophosphorylase showed the greatest reduction in catalytic activity after plants were returned to cooler conditions. Individual enzymes showed variation in the level of recovery under the cooler temperature conditions which followed the heating period.


Alloy Digest ◽  
1991 ◽  
Vol 40 (4) ◽  

Abstract UNS G62100 is a tough, shock resisting, case-hardening chromium-vanadium steel. It has high fatigue resistance in the heat treated condition. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-458. Producer or source: Alloy steel mills and foundries.


Alloy Digest ◽  
2020 ◽  
Vol 69 (1) ◽  

Abstract Lucefin Group C45U is a medium-carbon, non-alloy cold-work tool steel. It is primarily used in the non-heat-treated condition. For special applications it is used in the quenched and tempered condition. Owing to its low hardenability, C45U develops a fully hardened zone that is relatively thin, even when quenched drastically. Thicker sections have a hard case over a tough core. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming and joining. Filing Code: TS-784. Producer or source: Lucefin S.p.A.


2013 ◽  
Vol 21 (1) ◽  
pp. 43-51
Author(s):  
O. Bapokutty ◽  
◽  
Z. Sajuri ◽  
J. Syarif ◽  
◽  
...  

2017 ◽  
Vol 5 (10) ◽  
pp. 4835-4841 ◽  
Author(s):  
Pradip Pachfule ◽  
Xinchun Yang ◽  
Qi-Long Zhu ◽  
Nobuko Tsumori ◽  
Takeyuki Uchida ◽  
...  

High-temperature pyrolysis of Ru nanoparticle-encapsulated MOF (Ru@HKUST-1) afforded ultrafine Cu/Ru nanoparticle-embedded porous carbon composites (Cu/Ru@C), which show high catalytic activity for ammonia borane hydrolysis.


2012 ◽  
Vol 583 ◽  
pp. 285-288
Author(s):  
Dong Mei Zhao ◽  
Xue Peng Liu

By orthogonal design method, Catalytic activity of /ZrO2 solid superacid is studied, and the influence of catalyst characteristic and structure by manufacturing equipment is issued. It is concluded that the best prepared conditions of the superacid catalyst /ZrO2 for the synthesis of Octyl-Polyglycoside are followed:(1) PH=9.5; (2) calcined temperature at 500; (3) M(H2SO4)=0.5mol/L. Using this kind of catalyst the conversion of glueoside may reach as high as 96% in the synthesis of OCtyl-Polyglycoside and the selectivity is very high for the synthesis of Octyl-Polyglycoside. By introducing other metal oxide, the catalytic activity of complex solid superacid is studied.


Sign in / Sign up

Export Citation Format

Share Document