摘要
采用共沉淀法制备了不同配比的CuZnAlZr复合氧化物催化剂 ,并通过XRD和TPR等表征技术及活性评价 ,考察了催化剂各组分配比对活性的影响 ,从而对各组分配比进行了优化 .结果表明 ,组成为 (Cu7Zn3 ) 7(Al6Zr4) 3 的催化剂具有最高的催化活性 ,反应温度为 2 0 0℃时 ,甲醇转化率可高达 91 % ,而重整气体中CO的体积分数仅为 0 1 2 % .具有较高分散性及高还原性能的表相Cu组分的增加有利于提高催化剂的活性 ,Zn可以起到隔离和分散Cu的作用 ,而Al和Zr的存在可以稳定表相Cu2 +
Low temperature steam reforming of methanol is a relevant technique for on board supply of hydrogen for fuel cell vehicles. Recently, much attention was paid on oxidative steam reforming of methanol due to its quick response and auto thermal properties. This paper deals with the optimization of catalyst formulation of CuZnAlZr composite oxide system. The catalyst was prepared by co precipitation from aqueous solutions of Cu, Zn, Al and Zr nitrates and Na 2CO 3 (pH=7 6) at 65 ℃. The influence of the catalyst composition, such as the ratios of n (CuZn) / n (AlZr) , n (Cu) / n (Zn) and n (Al) / n (Zr) , on its catalytic performance for oxidative steam reforming of methanol to hydrogen was investigated. The optimized composition of the catalyst was (Cu 7Zn 3) 7 (Al 6Zr 4) 3. Over this catalyst, the methanol conversion reached 91% at 200 ℃, while the φ (CO) was only as low as 0 08%. The dispersion of CuO species and its occupation on the catalyst surface are the determining factors for the catalyst activity. The component Zn is responsible for the dispersion of CuO, while the components Al and Zr give assistance to stabilize the existence of Cu species on the catalyst surface.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2004年第7期523-528,共6页
关键词
氧化铜
氧化锌
氧化铝
氧化锆
合氧化物
醇氧化水蒸气重整
copper oxide, zinc oxide, alumina, zirconia, composite oxide, oxidative steam reforming of methanol
