IM-5分子筛在Ni-Cu催化剂甲烷热裂解制氢反应中的作用研究

甲烷热裂解制氢并生成高附加值的纳米碳材料,被认为是极具发展前景的氢气生产途径,但高性能催化剂的研发仍存在诸多挑战.我们选择多种载体(TS-1、 IM-5、 Y、介孔SiO₂、 γ-Al₂O₃、 CNTs),采用浸渍法制备Ni-Cu负载催化剂,通过低温N2吸附-脱附、 XRD、 SEM和H₂-TPR等系列表征方法对样品进行分析,考察不同载体对催化剂甲烷裂解制氢和纳米碳材料的影响.实验结果发现,分子筛载体独特的孔道结构有利于金属颗粒的分散,能有效避免反应中界面效应导致的催化剂失活,可提高催化剂反应活性并延长反应寿命,也显著提高了其碳产率.其中以IM-5分子筛为载体的催化剂表现最佳,在反应温度为700℃时, NiCu/IM-5催化剂甲烷转化率高达80%,氢气选择性达100%,反应400 min后活性未见明显降低. NiCu/IM-5催化剂碳产率高达1 446 g_C/g_cat,是NiCu/SiO₂催化剂的5.7倍, NiCu/γ-Al

Effect of IM-5 on the Methane Decomposition to Produce Hydrogen over Ni-Cu Bimetallic Catalyst

Zeolite ZSM-11 was synthesized by seed-assist method and treated with alkali to obtain the modified sample ZSM-11-AT. The physical and chemical properties of the samples ZSM-5, ZSM-11 and ZSM-11-AT were characterized and compared using XRD, N2 adsorption and desorption, XRF, TEM, NH3-TPD, and Py-IR. The specific surface area, pore structure and acid property of modified sample ZSM-11-AT had been improved. The catalytic performances of the samples were evaluated using a catalytic cracking fixed-bed device. The reactant conversion and products distribution between ZSM-5, ZSM-11 and ZSM-11-AT were compared. The results showed that ZSM-11 and ZSM-11-AT had advantage over ZSM-5 in terms of olefin (Ethylene and propylene) yield. The catalytic performance of ZSM-11-AT was further improved compared with ZSM-11.