摘要
丙酮酸是生产减肥药丙酮酸钙和Ｌ－氨基酸的原料，目前采用酒石酸脱水脱羧法合成，此工艺过程需要耗用大量的硫酸氢钾，不能回收，生产费用高，污染环境。近年来，Ｍ．Ａｉ等人采用Ｆｅ２Ｏ３－ＭｏＯ３ 等催化剂［１］，将乳酸酯氧化为丙酮酸酯，再水解为丙酮酸，而有关将钒氧化物用作乳酸乙酯制丙酮酸乙酯催化剂的研究报道则较少［２，３］。本文制备了以ＴｉＯ２、ＳｉＯ２、α－Ａｌ２Ｏ３等载体担载的钒氧化物催化剂，用ＸＲＤ、ＴＰＲ和ＩＲ等方法表征了钒氧化物在载体上的分散作用和氧化还原性能，以微量吸附量热技术考察了催化剂的表面酸性，研究了催化剂对乳酸乙酯选择性氧化制丙酮酸乙酯反应的活性，并试图将催化剂的组成、结构。
The structure and surface acidity of vanadium oxide supported on α Al 2O 3、TiO 2、SiO 2 have been studied by XRD、IR、TPR and adsorption microcalorimetry. The catalytic performance of the catalysts for selective oxidation of ethyl lactate to ethyl pyruvate was determined in a continuous flow fix bed reactor. The results showed that the dispersion of vanadium oxide on the supports weakened the V=O bond and actived the terminal oxygen, which increased the reaction activity. On the otherhand, The surface acidity is harmful to the selectivity of ethyl pyruvate. V/ α Al 2O 3 exhibited a lower conversion since its dispersion is low. The low selectivity on V/SiO 2 is due to its fairly strong surface acidity. Addition of K + weakened the surface acidty and enhanced selectivity of V/SiO 2. V/TiO 2 exhibited the best activity and selectivity among the catalysts studied because of its weak surface activity. The conversion of ethyl lactate and selectivity to ethyl pyruvate are 97% and 81%, respectively, over the V/TiO 2 catalyst at 473K.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
1999年第6期826-830,共5页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金
关键词
钒
催化剂
乳酸乙酯
丙酮酸乙酯
选择性氧化
vanadium oxide ethyl lactate ethyl pyruvate selective oxidation
