深度脱除CO的CuO/ZnO/ZrO_2催化剂

采用共沉淀法制备了 CuO/ZnO/ZrO_2催化剂,研究了 m(CuO):m(ZnO):m(ZrO_2)=70:15:15的催化剂脱除乙烯物料中 CO 的情况。在反应温度90℃、反应压力2 MPa、空速3 000 h~(-1)的条件下,CuO/ZnO/ZrO_2催化剂可将乙烯物料中体积分数为2.4×10~(-6)的 CO 深度脱除至3×10~(-8)以下,它的活性明显优于工业 BR9201(m(CuO):m(ZnO)=30:70)催化剂。采用 X 射线衍射、X 射线光电子能谱、H_2-程序升温还原、高分辨透射电子显微镜等于段对催化剂进行了表征。表征结果显示,CuO/ZnO/ZrO_2催化剂中的 ZrO_2主要以无定形的状态存在。对比工业 BR9201催化剂和 CuO/ZnO/ZrO_2催化剂得知,虽 CuO 质量分数从30%提高到70%,但 CuO 晶粒的尺寸由12.9 nm 减小到6.0 nm,ZrO_2的引入促进了 CuO 活性位的分散,大大提高了催化活性。

CuO/ZnO/ZrO2 Catalyst for Removal of Trace Amount of Carbon Monoxide in Ethylene

A new CuO/ZnO/ZrO_2 catalyst with m(CuO):m(ZnO):w(ZrO_2)=70:15:15 was prepared by co-precipitation and was used in removal of trace amount of carbon monoxide in ethylene. Under the conditions:90℃,2 MPa and GHSV 3 000 h~(-1) the CO in ethylene can be reduced from 2.4×10~(-6) (volume fraction) to lower than 3×10~(-8).Under the same reaction condition,by using commercial BR9201 CuO/ZnO catalyst with m(CuO):m(ZnO)=30:70,CO in ethylene can only be reduced to level of 3×10~7.Obviously CuO/ZnO/ZrO_2 catalyst shows better performance than BR9201 catalyst.The new catalyst was characterized by means of BET,XRD,XPS,H_2-TPR and HRTEM.ZrO_2 is found to exist in amorphous form.Comparing with BR9201 catalyst,although CuO content in the new catalyst increases from 30% to 70%,by introduction of amorphous ZrO_2 to the new catalyst,crystalline size of CuO decreases from 12.9 nm to 6.0 nm,which improve dispersion of active sites and lead to higher efficiency in carbon monoxide removal.So CuO/ZnO/ZrO_2 will become a potential industrial catalyst for removal of trace amount of carbon monoxide in ethylene to meet the requirement of ethylene polymerization.