摘要
采用共沉淀法制备得到CuO-ZnO-ZrO2催化剂及对比样品CuO-ZnO,通过XRD、BET、XPS、H2-TIR、H2-TPR等表征,考察了ZrO2的添加对CuO-ZnO-ZrO2催化剂的还原性能及其CO催化氧化性能的影响。与CuO-ZnO相比较,CuO-ZnO-ZrO2催化剂的比表面积增大、CuO和ZnO粒子的平均粒径减小、表面Cu粒子含量增多、还原性能得到显著提高,表明ZrO2的添加有利于提高CuO分散度,存在更多与ZnO相互作用的CuO微粒。TPR的还原动力学研究进一步证实了ZrO2对CuO还原性能的促进作用。在CO催化氧化反应中,CuO-ZnO-ZrO2样品的催化活性最高,并且还原温度对该催化剂的CO催化氧化性能影响显著,在160℃还原活化的催化剂具有77.3%的还原度,表现出较优的CO催化氧化性能。在50℃、3 MPa的反应条件下,CuO-ZnO-ZrO2催化剂可将液相丙烯中体积分数1.0×10-5的CO脱除低至2×10-8,连续反应1 500 min,稳定性能良好。
CuO-ZnO-ZrO2 catalyst was prepared by co-precipitation method. Its reducibility and catalytic performance in carbon monoxide oxidation at low temperature was studied through characterization by means of XRD, BET, XPS, H2-TIR and H2-TPR techniques. Compared with CuO- ZnO catalyst, CuO-ZnO-ZrO2 catalyst showed a larger surface area, smaller mean particle size of both CuO and ZnO, higher concentration of CuO on surface, and a remarkably improved reducibility, which indicated a higher dispersion of CuO particles in contact and interaction with ZnO particles. The results of the kinetic analysis based on the TPR profiles confirmed that ZrO2 played the role of a promoter for copper oxide reduction. CuO-ZnO-ZrO2 catalyst exhibited the highest activity compared with CuO-ZnO and pure CuO catalysts in carbon monoxide oxidation. The effect of reduction temperature on the catalytic activity of CuO-ZnO-ZrO2 was also discussed. The experiments revealed that the catalyst activated at 160 ℃ with proper reduction degree of 77.3% exhibited the best catalytic performance in the carbon monoxide oxidation and under the conditions of 50 ℃ and 3 MPa, it could remove the CO in liquid propylene,making its amount descending from 1.0 × 10-5 to lower than 2 ×10-8 with good stability during the continuous reaction of 1 500 min.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2012年第11期1066-1071,共6页
Fine Chemicals
基金
科技部转制院所专项(2011EG116066)
上海市科委启明星计划(11QB1402800)~~
