与SO42-/ZrO2/MCM-41主要表现为Lewis酸性不同,SO42-/TiO2和S2O82-/TiO2主要以Bronsted酸性为主,其中采用硫酸为促进剂制备的SO42-/TiO2具有最强的Bronsted酸性,而采用过硫酸根作为促进剂则使S2O82-/TiO2产生较SO42-/ZrO2/MCM-41更强的Lewis酸中心.研究发现,SO42-/TiO2和S2O82-/TiO2对假性紫罗兰酮催化环化...
The pyridine adsorption infrared (Py-IR) indicated that all of the OMSAs consisted mainly of Lewis acids. The OMSA was used to catalyse furfuryl alcohol in the synthesis of ethyl levulinate (EL). The maximum yield (80.6%) was obtained in the reaction conducted at 200 degrees C for 3 h....
It was found that anhydrous CuSO4 served as critical Lewis catalyst28 for the conversion of ribonolactone to 2,3-O-isopropylidene-d-ribonolactone. Although relatively high yield (72%) was achieved, the CuSO4 is hard to be fully recovered due to its excellent solubilty in water. Marek Marczews...
G Lewis,JP May,JE Mcclure - 《Bulletin of the American Mathematical Society》 被引量: 142发表: 1981年 Hypercomplex structures associated to quaternionic manifolds - ScienceDirect If M is a quaternionic manifold and P is an S1-instanton over M, then Joyce constructed a hypercomplex manifold we...
The pyridine adsorption infrared (Py-IR) indicated that all of the OMSAs consisted mainly of Lewis acids. The OMSA was used to catalyse furfuryl alcohol in the synthesis of ethyl levulinate (EL). The maximum yield (80.6%) was obtained in the reaction conducted at 200?°C for 3?h. The...