类水滑石衍生复合氧化物催化水解羰基硫的研究

Study of hydrolysis carbonyl sulfide over mixed oxides from hydrotalcite-like compounds

采用共沉淀法制备了一系列的类水滑石衍生复合氧化物催化剂,利用正交实验设计对催化剂的制备条件进行了优化,研究了金属组合、合成pH、M2+/M3+、二价金属比、焙烧温度和晶化温度等6个因素对羰基硫催化水解过程中催化剂硫容的影响。结果表明,金属组合、二价金属比和焙烧温度的影响极其显著(p=99%),晶化温度的影响显著(p=95%),合成pH与M2+/M3+对催化剂活性影响不显著(p=90%)。在设定实验条件下,金属组合取Co-Ni-Al、合成pH为9,M2+/M3+为3,二价金属比1,焙烧温度取350℃,晶化温度50℃时制得的催化剂具有最高的催化活性。对最佳制备条件下得到的催化剂进行了重复性实验以及XRD表征,结果表明制备的催化剂的硫容为7.10 g硫/g催化剂,Co3O4可能是其活性中心。

The orthogonal experiment design was employed to investigate the parameters of mixed oxides catalysts derived from a series of hydrotalcite-like compounds preparation through the coprecipitation method.The effects of metal combination,pH value,M2＋/M3＋,the ratio of divalent metal,calcination temperature,temperature of hydrothermal treatment on capacity of sulfur though hydrolysis COS were investigated.The results indicated that metal combination,the ratio of divalent metal and calcination temperature had notable effect on catalytic activity（p=99%）,and temperature of hydrothermal treatment had effect on catalytic activity（p=95%）,while pH value and M2＋/M3＋ had no notable effect（p=90%）.The catalysts prepared under following conditions exhibited superior catalytic activity： metal combination Co-Ni-Al,pH value of 9,M2＋/M3＋ of 3,divalent metal ratio of 1,calcination temperature of 350℃,hydrothermal treatment temperature of 50℃.Moreover,the catalyst under the optimized conditions of preparation was characterized by repetitive experiment and XRD.The results indicated that the sulphur capacity of the catalyst reached 7.10 g sulfur/g catalyst and the Co3O4 may be active center.