For simple compositions, SiO2 and feldspar melts have higher D (~0.44–0.50 mm2 s−1) than soda–lime silicate and pyroxene melts (~0.29–0.38 mm2 s−1). Rock melts show the trend even more clearly, with D varying from ~0.52 mm2 s−1 for rhyolite and leucogranite to ~0.25 mm2 ...
The catalyst can be used for catalyzing cellulose hydrolysis and dewatering to generate 5-hydroxymethylfurfural. The product has a multi-porous structure and can increase the specific area of the catalyst; the surface has vast super acids; the catalyst has excellent performance in catalyzing cellulose...
Examples of suitable Lewis basis of the structure RC(NR)N include 1,5,7-Triazabicyclo[4.4.0]dec-5-ene; 7-Methyl-1,5,7-triazabicyclo4.4.0dec-5-ene; 2,3,4,6,7,8,9,10-Octahydropyrimidol[1,2-a]azepine, (DBU). Examples of suitable guanidines include guanidine, biguanidine, and 1,...
Metathesis of ethylene and 2-butene over MoOx/Al2O3-SiO2: Effect of MoOx structure on formation of active sites and propene selectivity J. Catal. (2018) H. Zhu et al. Sn surface-enriched Pt–Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation J. Catal...
References Antignano A, Manning CE (2008) Rutile solubility in H2O, H2O–SiO2, and H2O–NaAlSi3O8 fluids at 0.7–2.0 GPa and 700–1000 °C: implications for mobility of nominally insoluble elements. Chem Geol 255:283–293 Arai S (1975) Contact metamorphosed dunite-harzburgite...
for 30 minutes. The annealed film had crystallized to the cubic tungsten structure and lost its nitrogen to become pure tungsten metal. EXAMPLE 4 Example 3 was repeated, except that the tungsten nitride film was deposited directly on silicon without an oxide interlayer produced by the UV-ozone...
Al2O3 or SiO2 particles with abundant surface hydroxyl groups can prevent side reactions of aromatic compounds with AlCl3 completely; this Lewis acid can potentially destroy the stable structure of aromatic compounds to a large extent. This discovery was successfully utilized in the highly efficient ...
La sites supported on silica (La-SiO2) with a similar chemical structure but no H-bonding interaction with Si–OH groups were prepared for comparison. Lewis acid La sites promote AcH aldol condensation, and the activity of such sites is nearly identical for both La-DeAlBEA and La-SiO2. The...
The evidence for the Al-doped MCM-41 structure was confirmed by XRD, IR, 27Al MAS NMR and 29Si MAS NMR results. Besides, 27Al MAS NMR revealed the existence of both Al framework and extra-framework. FTIR-pyridine adsorption demonstrated the formation of Brønsted and Lewis acidity, and ...