摘要
在２５ ℃下，将０－５ ｍｏｌ／Ｌ的氨水滴加到不同配比的二氯氧锆和硝酸铈（ Ⅲ） 的混合溶液中，经过滤、洗涤，制备了不同质量分数的三氧化二铈和二氧化锆的混合物，再经０－５ ｍｏｌ／Ｌ的稀硫酸浸渍１ ｈ、过滤、１００ ℃干燥１ ｈ，最后分别在５５０、６５０ 和７００ ℃焙烧４ ｈ 制得了一系列的含铈固体超强酸ＳＯ４２－／ＺｒＯ２Ｃｅ２Ｏ３ 。发现加入质量分数为０－５％ ～２％ 的三氧化二铈可使其对环己醇脱水活性显著提高，过高的酸强度不利于环己烯的生成，其中以５５０ ℃时焙烧制得的固体超强酸ＳＯ４２－／ＺｒＯ２Ｃｅ２Ｏ３［ ｗ（Ｃｅ２Ｏ３）＝ １－５％ ］ 的催化活性及环己烯的选择性最好，在１４０ ℃下，环己醇的转化率为９５－３ ％ ，环己烯的选择性高达１００％ 。并分别用正己烷和吡啶做探针分子对其进行了差动热分析研究，结果表明加入质量分数为０－５％ ～２％ 的三氧化二铈使ＳＯ４２－／ＺｒＯ２Ｃｅ２Ｏ３ 超强酸酸强度和酸总量得到不同程度的提高。
The mixtures of ZrO\-2 and Ce\-2O\-3 were prepared by adding 0 5 mol/L aquoues ammonia to the solution of ZrOCl\-2 with different content of Ce(NO\-3)\-3.The solid superacids SO 4 2- /ZrO 2 Ce 2O 3 were obtained by impregnating above mixtures with 0 5 mol/L H\-2SO\-4 for 1 h,which were filtrated,dried for 1 h at 100 ℃,and calcined for 4 h at 550,650 or 700 ℃.It was found that by adding 0 5%～2 0% Ce 2O 3 to SO 4 2- /ZrO 2 superacid,its catalytic activity on cyclohexanol dehydration was improved obviously.The superacid SO 4 2- /ZrO 2 Ce 2O 3[w(Ce 2O 3)=1 5%] calcined at 550 ℃ possessed the optimum catalytic properties with 95 3% conversion of cyclohexanol and 100% selectivity of cyclohexene at 140 ℃.The differential scanning calorimetry of n C\-6H 14 and pyridine as probe molecules on these superacids were investigated respectively,and the results showed that the acid strength and total acid amount of these solid superacids all increased with appropriate addition of Ce\-2O\-3.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2000年第2期88-90,共3页
Fine Chemicals
关键词
超强酸
环己醇脱水
环己烯
催化剂
SO 4
2- /ZrO 2 Ce 2O 3
superacid
cyclohexanol dehydration
