摘要:采用浸涂法将自制的介孔空心SiO2纳米粉体涂覆到堇青石基体上,然后采用微波法负载活性组分Pd和助剂Ni制备了纳米涂层整体式加氢催化剂,并考察空速、涂层增重、Ni助剂添加量等因素对其乙炔选择性加氢催化性能的影响。结果表明:经过涂覆后的堇青石整体式催化剂加氢性能与未涂覆时相比有了显著提高,且添加适量的助剂Ni有助于催化性能的进一步改进。在反应温度为54℃、压力为0.1 MPa、空速为3 800 h-1的条件下,使用涂层增重质量分数为6%、Ni与Pd物质的量比为4∶1的催化剂,当乙炔接近完全转化时,乙烯选择性能够到达40.9%。
关键词: 整体式催化剂;纳米材料;涂覆;选择性加氢
Abstract: A novel cordierite monolithic catalyst with porous hollow silica nano-particles as washcoat was prepared by a dip-coating method and the Pd active component and Ni promoter were loaded by a microwave method. The performance of the prepared catalysts for selective hydrogenation of acetylene was investigated at varying space velocity, the porous hollow silica nano-particles coating amount and Ni loading amount. It was found that the coating of porous hollow silica nano-particles on the cordierite substrate could significantly promote the catalytic performance. When the space velocity was 3 800 h-1, the mass fraction of coating on porous hollow silica nano-particles was 6%, the molar ratio of Ni and Pd was 4∶1, the reaction pressure was 0.1 MPa and reaction temperature was 54 ℃ , the ethylene selectivity of the novel catalyst still remained 40.9% when the acetylene was nearly completely converted.
Keywords: monolithic catalyst; nano-sized materials; coating; selective hydrogenation