掺杂型负载金属催化剂在甲烷裂解反应中的研究进展

Review of Doped Metal Catalyst Used in Methane Catalytic Decomposition

甲烷催化裂解反应能够同时制取不含碳氧化物的高纯氢和纳米碳材料,引起研究界的广泛关注。Ni、Fe和Co是常用的甲烷裂解反应的催化剂的活性组分,但单活性组分的负载型金属催化剂往往存在转化率低和寿命短等缺点,通过催化剂的设计改进其性能是催化剂研究工作的重要方向之一。除了制备方法的选择和反应条件的优化,利用不同金属组分性质间的差异,在其中引入第二或第三组分,同样能够有效改善催化剂的性能。对掺杂型负载金属催化剂的研究进行了综述。概述了催化剂的失活机理及模型(活性位覆盖模型和孔道口堵塞模型),以及如何从失活原因出发进行掺杂型负载金属催化剂的设计。根据掺杂元素作用方式不同,分类介绍了当前掺杂型负载金属催化剂的主要研究成果及其未来的发展方向。

Methane catalytic decomposition can produce COx-free hydrogen and carbon nanomaterials simultaneously, which has attracted extensive attention. Ni, Fe and Co based catalysts are commonly used in methane catalytic decomposition. However, the catalysts with single active component always show low activity and short lifetime. The catalyst design is important in improving the catalytic properties. Besides preparation methods and reaction conditions, introducing a second or third component may improve the catalyst performance due to the different interaction between the metals. This review summarizes the in- vestigation on doped metal catalysts. The deactivation mechanism is firstly presented, active sites blocking and pore mouth plugging models are the alternative mechanisms, based on which the doped metal catalyst could he designed. The main achievements are introduced, which are divided into four parts due to the different roles of the doped elements, including the harmful elements which should be kept away. The functional mechanisms of the doped elements are summarized and the direction of future is pointed out.