Abstract

The activity of catalytic systems based on polyoxometalates in the gas-phase dehydration of glycerol into acrolein has been investigated. The catalysts synthesized have been characterized using FTIR spectroscopy, X-ray phase analysis, scanning electron microscopy, and low-temperature nitrogen adsorption/desorption (BET method). It has been shown that the nature of the surface acid sites of catalysts has a significant effect on the direction of glycerol transformation. An increase in the fraction of Brønsted acid sites in the catalyst leads to an increase in the yield of acrolein. At the same time, an increase in the fraction of Lewis acid sites in the catalyst leads to an increase to the yield of acetol, which is formed through a competing route. Among the catalytic systems considered, the best results have been obtained with the silicomolybdic acid anion supported onto alumina (SiMo/A). The main patterns of the gas-phase glycerol dehydration have been studied using SiMo/A as a catalyst, and the conditions responsible for the highest yield of acrolein have been determined.

中文翻译：

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多金属氧酸盐存在下甘油的气相脱水成丙烯醛

摘要

研究了基于多金属氧酸盐的催化体系在甘油气相脱水成丙烯醛中的活性。合成的催化剂已使用FTIR光谱，X射线相分析，扫描电子显微镜和低温氮吸附/脱附（BET法）进行了表征。已经表明，催化剂的表面酸位的性质对甘油转化的方向具有显着影响。催化剂中布朗斯台德酸位点的分数增加导致丙烯醛的产率增加。同时，催化剂中路易斯酸位点分数的增加导致通过竞争途径形成的丙酮醇的产率增加。在所考虑的催化系统中，用硅钼酸阴离子负载在氧化铝上（SiMo / A）可获得最佳结果。以SiMo / A为催化剂，研究了气相甘油脱水的主要方式，并确定了丙烯醛收率最高的条件。