Synthesis Of Mesoporous Carbon-base Solid Acid Catalyst And Its Performance Study

Solid acid catalysises have many advantages, such as excellent catalytic activity, highselectivity, non-corrosiveness, environmental-friendly, good reusability and so on, so manyresearchers have paied much attention on them. Conventional solid acid, such as sulfated metaloxide (SO42-/MxOy), zeolite molecular sieve ect., have high catalytic activity, however, its activeingredients are caduceus and its recyclability is bad. Because carbon-base solid acids possessexcellent thermostability, high catalytic performance and remarkable reusability, it has been thehot topic in the field of solid acids. Traditional carbon-base solid acid catalysts own manydisadvantages, such as low surface area, poor porosity, high carbonization temperature andrelatively low acidity and so on. Consequently, the current researches in this area have focusedon designing and synthesizing non-toxic mesoporous carbon-base solid acid catalysts with highsurface area, good porosity and high acidity. In this dissertation, mesoporous carbon-base solidacids have been used as research object to prepare a series of mesoporous carbon-base solid acidcatalysts via different methods. Meanwhile, the obtained materials were characterized by SEM,TEM, XRD, N2adsorption-desorption and so on. Their catalytic performances were investigatedby the esterfication and transesterfication of aliphatic acid and soybean oil with short-chainalcohol. The detailed works were summarized as follows:1. Sulfonated mesoporous carbon/silica composite solid acid with large surface area, highacidity, excellent catalytic performance, superior stability and recyclability was prepared byhydrothermal route in low temperature with using glucose as carbon source and mesoporoussilica (SBA-15) as support, and sulfonation process adopted a post-grafted method withconcentrated sulfuric acid. This solid acid was investigated catalyzing the esterification of oleicacid with methonal to estimate its catalytic activity.2. A H2O2pretreatment of hard-template prepared ordered mesoporous carbon (OMC)material introduced a high content of hydrophilic groups on carbon surface, which subsequentlyresulted in a high level of modification of–SO3H groups and obtained sulfonated mesoporouscarbon solid acid with high acidity and multi-functionalized group. OMC–H2O2–SO3H solid acidshows a much higher catalytic activity, which is almost twice as high as that of OMC–SO3H. 3. Sulfonated mesoporous carbon solid acid with high acidity and superior mesoporousstructure was synthesized by slufonating the soft-template prepared mesoporous carbon. Theinfluence of carbonization temperature on the pore structure and acidity was studied. Theexperimental results showed that the sulfonated catalyst carbonized at a low temperature (400°C)showed the highest acidity of2.21mmol H+g-1, meanwhile, retained a superior mesoporousstructure and relatively large surface area, which resolve the contradictory issue among thecarbonization temperature, acidity and mesoporous structure.4. Magnetically separable porous carbon nanaspheres were obtained by a simple chemicalactivation with ZnCl2. After the treatment of sulfonation, this porous carbon solid acid possessedhigh surface area, high acidity, superior porosity and magnetically separable properity.Meanwhile, we studied its catalytic performance for the esterification of aliphatic acid andtransesterification of soybean with methanol.