Zn-ZrO_2/SiO_2非氧化脱氢制无水甲醛的研究

在微型固定床反应器中对Zn-ZrO2/SiO2催化甲醇直接非氧化脱氢制备无水甲醛进行了研究。实验中考察了催化剂组成、反应温度及质量空速对脱氢反应的影响。结果显示,在进料气中φ(CH3OH)为35%,反应温度为800K,质量空速为35mL/(g.s)的优化反应条件下,甲醇的转化率达到100%,甲醛的选择性为63%。结合催化剂的活性评价及X射线光电子能谱、电子扫描电镜、热重等技术显示,采用均匀沉淀法制备的Zn-ZrO2/SiO2催化剂,活性组分能均匀分散在载体上,且对甲醇的非氧化脱氢具有高效的催化作用。助剂ZnO的引入可以有效抑制反应过程中催化剂的烧结,极大程度的增强催化剂的稳定性。

Nonoxidative methanol dehydrogenation to anhydrous formaldehyde over Zn-ZrO/SiO2 catalyst

Methanol direct dehydrogenation to anhydrous formaldehyde using Zn-ZrO2/SiO2 as catalyst was studied in a fixed-bed microreactor.Effects of catalyst composition,reaction temperature,space velocity on the dehydrogenation reaction were investigated.It was found that under the optimized conditions of feed gas methanol volume fraction of about 35%,reaction temperature of 800K,space velocity of about 35ml.g-1.s-1,the conversion rate of methanol reached 100%,and the selectivity to formaldehyde was 63%.The results of XRD,SEM,TG measurements and catalyst evaluation showed that the catalysts prepared by uniform co-precipitation had active components uniformly dispersing on them,which exhibited excellent performances for methanol direct dehydrogenation.Doping ZnO promoter into the ZrO2/SiO2 catalyst could effectively inhibit its sintering during reaction and thus greatly enhance the stability of the catalyst.