助剂对CuO-ZnO-ZrO_2催化剂CO_2加氢制甲醇性能的影响  

Effect of Promoters on Performance of CuO-ZnO-ZrO_2 Catalyst Prepared for CO_2 Hydrogenation to Methanol

作　　者：李培培[1] 秦玉才[1] 李强[1] 莫周胜[1] 张媛媛[1] 宋丽娟[1] 

机构地区：[1]辽宁石油化工大学辽宁省石油化工催化科学与技术重点实验室,辽宁抚顺113001

出　　处：《石油化工高等学校学报》2016年第3期12-17,共6页Journal of Petrochemical Universities

基　　金：国家自然科学基金项目(21076100)

摘　　要：采用燃烧法制备了Al2O3、CeO_2、NiO金属氧化物改性的CuO-ZnO-ZrO_2催化剂,通过X射线衍射(XRD)、H2-程序升温还原(H2-TPR)、H2-程序升温脱附(H2-TPD)、CO_2-程序升温脱附(CO_2-TPD)表征手段,探讨Al2O3、CeO_2、NiO助剂对催化剂物相组成及微观结构的影响,且在固定床连续流动反应装置上考察了添加3种不同助剂对CO_2加氢合成甲醇性能的影响。结果表明,Al2O3、CeO_2、NiO助剂均有助于提高CuO-ZnO-ZrO_2催化剂的活性,且添加适量CeO_2的催化剂催化效果最好;3种助剂都可以抑制CuO晶粒的生长和提高CuO的分散度,从而更利于催化剂的还原和H2的吸附解离;3种金属氧化物助剂均可不同程度地调变催化剂表面碱强度和碱性位数目,较之NiO改性的催化剂,Al2O3和CeO_2改性的催化剂表面碱强度更强,碱性位数目也更多,从而更利于CO_2的吸附活化。CuO-ZnO-ZrO2 catalyst was modified by combustion method, using Al2O3, CeOz, NiO metal oxides as promoters. The effects of Al2O3, CeO2, NiO on phase composition and catalyst structure were illuminated by using X- raydiffraction （XRD）, temperature-programmed reduction ofhydrogen （H2-TPR）, temperature-programmed desorption of hydrogen （H2-TPD） and carbon dioxide （CO2-TPD） techniques. And the effects of the three chosen promoters on catalytic performance for CO2 hydrogenation to methanol were studied in a fixed-bed plug flow reactor. The results indicated that the three promotes of Al2O3, CeO2, NiO all contributed to improving theactivity of catalysts and CeO2-modified catalyst had best catalytic performance. Moreover, the three promotes all could inhibit CuO crystal grain growth and improve the dispersion of CuO, which could benefit the reduction of catalysts and H2 adsorption-dissociation. Besides that, the three metal oxides could modulate the intensity amount of basic sites on the catalyst surface in different degrees. Comparing with NiO-modified catalyst, CeO2-modified catalyst and Al2O3- modified catalyst both possessed higher basic intensity and more basia sites, which led to COs adsorption-activation easily.

关 键 词：二氧化碳加氢 甲醇 燃烧法 CuO-ZnO-ZrO2催化剂 助剂 

分 类 号：TE624.4[石油与天然气工程—油气加工工程] TQ426[化学工程]