(Ni_(0.8)Fe_(0.2))(Pr_kZr_(1-k))_4O_x催化剂的制备及其乙醇水蒸气重整催化性能

(Ni_(0.8)Fe_(0.2))(Pr_kZr_(1-k))_4O_x Catalyst Preparation and Catalytic Activity Evaluation for Ethanol Steam Reforming

用共沉淀法制备Pr_kZr_(1-k)O_y载体,浸渍法制备(Ni_(0.8)Fe_(0.2))(Pr_kZr_(1-k))_4O_x系列催化剂,并将其用于乙醇水蒸气重整反应。通过X射线粉末衍射(XRD)、程序升温还原(TPR)和比表面积测试(BET)对催化剂的晶体结构、还原特性和比表面积进行表征。结果显示,催化剂具备立方晶相ZrO_2骨架;Pr组分可以进入到ZrO_2的晶格中,随着Pr比例的增加,载体和催化剂中ZrO_2骨架的晶格常数都有所增加,(Ni_(0.8)Fe_(0.2))(Pr_(0.2)Zr_(0.8))_4O_x催化剂显示出最好的还原活性、高温ESR活性和H_2选择性。以SDBS为分散剂制备出的(Ni_(0.8)Fe_(0.2))(Pr_(0.2)Zr_(0.8))_4O_x催化剂具有更大的比表面积,其催化活性更高,在600℃时乙醇转化率可达99.37%,H_2、CO、CH_4和CO_2的摩尔分数分别为76.43%、3.55%、8.45%和11.65%,在整个反应过程中未发现催化剂失活。

PrkZr1-k Oy composite oxide was synthesized with co -precipitation method and （Ni0.8 Fe0.2 ） （PrkZr1-k）4Ox cat- alysts, which were then used in ethanol steam reforming, were prepared by impregnation. X - ray diffraction （ XRD）, H2 tem- perature program reduction （HE -TPR） and specific surface area measurements （BET） techniques were used to characterize the crystal phases, reduction properties and specific surface features of the catalysts. The results indicated the catalysts are in ZrO2 cubic crystal phase. Pr component could enter ZrO2 lattice, and lattice constant of ZrO2 skeleton in the supports and cat- alysts increase with the Pr content. Among all catalysts studied, （Ni0.8 Fe0.2 ）（ Pr0.2Zr0.8 ）4Osexhibit top reduction activity, high- temperature ESR activity as well as the selectivity of HE. Higher specific surface area and catalytic activity were a- chieved when （Ni0.8 Fe0. 2 ） （Pr0. 2 Zr0. 8 ）4Ox catalysts were prepared with SDBS as the dispersant. Ethanol conversion can reach 99.37% and the molar fraction of H2, CO, CH4 and CO2 are 76. 43%, 3.55%, 8.45% and 11.65% respectively under 600 ℃. No catalyst deactivation was detected during the whole process.