Reduction time effect on structure and performance of Ni-Co/MgO catalyst for carbon dioxide reforming of methane
Reduction time effect on structure and performance of Ni-Co/MgO catalyst for carbon dioxide reforming of methane
复制标题
还原时间对甲烷二氧化碳重整Ni-Co/MgO催化剂结构和性能的影响
DOI：
10.1016/j.ijhydene.2014.10.086
复制
发表时间：
2014
影响因子：
7.2
通讯作者：
Li Wenying
中科院分区：
文献类型：
--
作者：
Huo Junmei;Jing Jieying;Li Wenying
用氢气还原催化剂是二氧化碳重整甲烷的重要过程，因为金属活性中心在还原过程中暴露并分散。采用多次浸渍法制备了Ni-Co/MgO催化剂，并将其用于甲烷二氧化碳重整反应。活性评价表明，还原1 h的催化剂表现出良好的上级催化活性，甲烷和二氧化碳转化率分别为92%和97%，合成气比例接近1（0.98）。高活性归因于较好的金属分散（10.5%）和较小的活性金属颗粒尺寸（10 nm）。拉曼光谱分析表明，还原时间越长，催化剂活性金属粒径越大，越容易形成石墨状碳沉积，而碳沉积物很难被CO2解离产生的活性氧物种去除。
Reducing catalysts with hydrogen is an important process for carbon dioxide reforming methane since metallic active sites are exposed and dispersed during the reduction process. In this work, Ni–Co/MgO catalysts were prepared for syngas production by using a multiple-impregnation method with a carbon dioxide reforming methane reaction. Activity evaluation showed that catalysts that reduced for 1 h exhibited superior catalytic activity with methane and carbon dioxide conversion at 92% and 97%, respectively, and the syngas ratio close to unity (0.98). The high activity is ascribed to the better metal dispersion (10.5%) and smaller active metal particle size (10 nm). Raman spectra analysis indicated that catalysts that reduced for a longer time possessed larger active metal particle size, and were more susceptible to the formation of graphite-like carbon deposits, which were difficult to be removed by the active oxygen species derived from carbon dioxide dissociation.