【作者】 王晓红；

【导师】 黄伟；

【作者基本信息】 太原理工大学 ， 化学工艺， 2002， 硕士

【摘要】 CH₄-CO₂低温转化直接合成含氧有机物是C₁研究领域最具挑战性的课题之一。本文综述了CH₄在催化剂表面的活化，低碳烷烃的羰基化和羧基化，CO₂的活化与转化，CH₄与CO₂的共活化及相互反应等研究进展，并以此为基础设计了CH₄-CO₂低温转化直接合成含氧有机物的催化剂及反应的进料方式，利用扫描电镜，红外，热分析，比表面测定等分析手段，结合催化剂的活性评价，对所设计催化剂进行了基础性研究，对反应的进料方式做了初步探讨，通过研究得出如下结论： （1）本文所研究的CuCo，CuCoZr及RuCo三种类型催化剂对CH₄-CO₂低温转化合成含氧有机物均有活性，在这些催化剂表面，CO₂与CH₄活化后所生成的表面碳物种反应可生成乙酸，乙醇，丙酮等两个以上碳的含氧有机物。其中乙酸的选择性最高。反应后三种催化剂表面均较少积碳。 （2）三种催化剂中CuCoZr类催化剂尤其是低Cu／Co比的CuCoZr类催化剂由于具有较大的活性比表面积，低的产物吸附性能而显示较高的活性。 （3）催化剂使用过程中结构及表面形态发生了很大的变化，表面由疏松多孔变得较为致密，催化剂颗粒团聚，孔数目减少，从而导致催化剂的比表面积大大下降。 （4）离子交换法制备的RuCo分子筛载体催化剂，使用后的催化剂上可观察到邻羟基苯乙酮的官能团。 （5）在CH₄／CO₂交替进料方式下，在较高温度下反应生成有机物的总碳转化率要高于低温的情况。 （6）与CH₄／CO₂交替进料方式相比，混氢及加氧进料方式都太原理工大学硕士学位论文能提高乙酸收率，其中混氢比例合适的cH4/C 02+HZ与CH4+CoZ/H:方式最具潜力，但需要很好地控制CO:加氢. （7）催化剂及进料方式对产物分布都有影响，贵金属催化剂可以在一定程度上抑制C02加氢. （8）热力学最有利的加氧方式由于本文所研究的催化剂体系不合适而未能收到预期的效果. （9）CH4+C02/H:进料方式较有利于乙醇的生成.CH4/CoZ+HZ进料方式则对丙酮的生成较有利. （l0）在CH4活化过程中混氢，可以抑制CH4的深度脱氢，从而提高甲烷的转化率及乙酸的收率，13.8%的混氢比例对cH4的转化最有利，此时乙酸的收率达最大值.但选择性却最小. （11）在二氧化碳反应的过程中混氢可以提高乙酸收率，当混氢比例为50%时乙酸收率达最大，但此时乙酸的选择性最小.更多还原

【Abstract】 It is one of the most challenging subjects to form oxygenate compounds directly from methane and carbon dioxide at low temperature in the C, field. In this paper, the activation and conversion of methane and carbon dioxide, the functionalization of alkanes, the mutual activation and conversion of methane and carbon dioxide are reviewed. Based on the review, some processes of direct converting CHx and CO2 to oxygenate compounds at low temperature are suggested and some catalysts used in these processes are designed. The catalysts have been studied here using the SEM, FTIR,TG-DTA, and BET analytical methods combined with the reactivity evaluation ; the processes have also been principally probed. Here are some conclusions:(1)The three kinds of CuCo,CuCoZr and RuCo catalysts all have reactivity for the low temperature conversion of methane and carbon dioxide. On the surface of these catalysts some ethanol, acetic acid, acetone and so on have been observed. Of all these substances, acetic acid’s selectivity is the highest. All these catalysts have little carbon deposition after reaction.(2)As the CuCoZr catalysts especially the low Cu/Co ratio catalysts have relatively big specific surface area, low ability of adsorbing products, their reactivity are higher.(3)During the catalytic reaction , the catalysts’ structure and configuration have been changed a lot. The surface has become compacted and the number of the pores has decreased. These lead tothe reduction of the specific surface area.(4)Some functional groups of o-hydroxyl phenyl acetone have been observed by FTIR analysis on RuCo catalyst after reaction.(5)In the CH4/CO2 process, the convertion of total carbon is higher at higher temperature.(6)Compared with CH4/CO2 process the processes of mixing hydrogen or oxygen with the feed gas all can improve the yield of acetic acid. The CH4/CO2+H2 process with suitable hydrogen proportion and the CH4+CO2/H2 process are more favorable. But some methods should be adopted to control the carbon dioxide’s hydrogenation.(7)The catalysts and the processes all have influence on the products’ distribution. The novel metal can control the carbon dioxide’s hydrogenation to some extend.(8)As the catalysts are unsuitable for the reaction under oxygenate atmosphere, the CH4+CO2+O2 process has not got the expected result in present work.(9)The CH4+CO2/H2 process is more favorable for the formation of ethanol. The CH4/CO2+H2 process is more favorable for the formation of acetone.(10)When the proportion of hydrogen in the mixture ofhydrogen and methane reaches 13.8 %,the yield of acetic acid reaches the highest, but its selectivity is the lowest.(11)When the proportion of hydrogen in the mixture ofhydrogen and carbon dioxide reaches 50 %,the yield of acetic acid reaches the highest and its selectivity is the lowest.更多还原