甲烷制合成气Ni基催化剂评述

Ni-Based Catalyst for Syngas Preparation by Partial Oxidation of Methane

综述了甲烷氧化制合成气的Ni基催化剂的研究意义和现状。对不同晶型的Al2O3载体及载量进行了系统的阐述。由于其表面酸中心较容易积炭,可添加稀土金属、碱金属、碱土金属、贵金属助剂或其混合物,以增强催化剂表面的碱性,提高催化剂的抗积炭性能。讨论了可能发生的积炭反应以及温度对反应平衡常数的影响,对积炭的原因、积炭的形状及影响积炭的因素进行了论述。直接反应机理是目前制合成气比较公认的反应机理,论述了Ni催化剂上CH4制合成气的活性位及原理,同时对透氧膜的透氧机理、透氧量及其在制合成气方面的应用进行了综述及展望。

The significance and status quo of the Ni - based catalyst for preparing syngas by partial oxida- tion of methane is introduced, and the A1E 03 carriers of different crystal forms and their load capacities are dis- cussed systematically. Because coke can deposit at the acidic centers of catalyst surface easily, a promoter of earth metal, alkali metal, alkaline earth metal or noble metal or a mixture of said promoters can be added to increase the alkaline of catalyst surface and improve the coke deposit resistant property of catalyst. The possi- ble coke deposit reaction and the effect of temperature on reaction equilibrium constant as well as the cause for coke deposit, the shape of coke deposit and the factors affecting coke deposit are discussed. The direct reac- tion mechanism is the recognized reaction mechanism for syngas preparation at the present time. The active sites on Ni - based catalyst for the preparation of syngas with CH4 are introduced, and the oxygen permeation mechanism of oxygen permeable membrane, oxygen permeation volume and the application of oxygen permea- ble membrane in the preparation of syngas are discussed.