掺氮炭材料的制备及其乙炔氢氯化性能研究

发布时间：2018-09-04 14:00

【摘要】：随着环保要求的提高,涉汞催化剂的替代已成为电石法聚氯乙烯产业发展的瓶颈。炭基非金属无汞催化剂具有成本低廉,耐腐蚀性及耐热性能好等特点,是目前无汞触媒研发中的一个重要方向。本论文对商品活性炭的表面改性及中孔淀粉炭的制备方法进行了研究,关联了炭材料的表面化学基团、灰分、氮掺杂等和乙炔氢氯化催化性能之间的关系,得到以下结论:1.商业活性炭的表面羧基等酸性含氧基团含量越高,乙炔氢氯化活性及稳定性越差;活性炭的灰分含量越低,催化剂活性越好;在比表面积、灰分、孔隙结构都接近的情况下,不同来源的活性炭乙炔氢氯化反应活性顺序如下:煤质炭木质炭椰壳炭,其活性可能和活性炭的石墨化程度有关。2.商品活性炭通过尿素改性可引入含氮基团,氮含量随焙烧温度的降低而提高,改性后的活性炭乙炔氢氯化活性随氮含量的提高而线性增加。3.以小麦淀粉为碳源,采用固相研磨的硬模板法,成功制备了成型的中孔淀粉炭,和活性炭及蔗糖为碳源制备的中孔炭相比,中孔淀粉炭具有更好的乙炔氢氯化催化性能。在固相碾磨的过程中可加入三聚氰胺调节氮含量。当炭材料中的氮含量低于4%时,氮掺杂中孔淀粉炭的乙炔氢氯化活性随氮含量增加而增加;当氮含量高于4%时,其乙炔转化率基本不变。
[Abstract]:With the improvement of environmental protection requirements, the substitution of mercury-related catalysts has become the bottleneck of the development of calcium carbide polyvinyl chloride industry. Carbon-based non-metallic mercury-free catalysts have the advantages of low cost, good corrosion resistance and heat resistance, which is an important direction in the research and development of mercury-free catalysts. In this paper, the surface modification of commercial activated carbon and the preparation of mesoporous starch carbon were studied. The relationship between the surface chemical groups, ash, nitrogen doping and catalytic properties of acetylene hydrochlorination was studied. The higher the content of acidic oxygen groups such as carboxyl group on the surface of commercial activated carbon, the worse the activity and stability of hydrogen chlorination of acetylene; the lower the ash content of activated carbon, the better the activity of catalyst; when the specific surface area, ash and pore structure are close to each other, The order of activity of acetylene hydrochlorination of activated carbon from different sources is as follows: the activity of charcoal wood coconut shell charcoal may be related to the graphitization degree of activated carbon. Commercial activated carbon can introduce nitrogen-containing groups through urea modification, the nitrogen content increases with the decrease of calcination temperature, and the hydrogen-chlorination activity of modified activated carbon increases linearly with the increase of nitrogen content. Mesoporous starch carbon was successfully prepared by solid phase grinding with wheat starch as carbon source. Compared with activated carbon and sucrose as carbon source, mesoporous starch carbon has better catalytic performance for hydrogen acetylene chlorination. Melamine can be added to adjust nitrogen content in the process of solid-phase milling. When the nitrogen content in carbon is lower than 4, the activity of acetylene hydrochlorination of N-doped mesoporous starch carbon increases with the increase of nitrogen content, but when nitrogen content is higher than 4, the conversion rate of acetylene is almost unchanged.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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