Abstract:
The increasing demand for clean fuels and sustainable products has attracted much interest in the development of active and selective catalysts for CO conversion to desirable products. This review maps the theoretical progress of the different facets of most commercial catalysts, including Co, Fe, Ni, Rh, and Ru. All relevant elementary steps involving CO dissociation and hydrogenation and their dependence on surface structure, surface coverage, temperature, and pressure are considered. The dominant Fischer-Tropsch synthesis mechanism is also explored, including the sensitivity to the structure of H-assisted CO dissociation and direct CO dissociation. Low-coordinated step sites are shown to enhance catalytic activity and suppress methane formation. The hydrogen adsorption and CO dissociation mechanisms are highly dependent on the surface coverage, in which hydrogen adsorption increases, and the CO insertion mechanism becomes more favorable at high coverages. It is revealed that the chain-growth probability and product selectivity are affected by the type of catalyst and its structure as well as the applied temperature and pressure.
摘要:
对清洁燃料和可持续产品的不断增长的需求吸引了人们对开发用于将CO转化为所需产品的活性和选择性催化剂的极大兴趣。这篇综述绘制了大多数商业催化剂不同方面的理论进展,包括Co,Fe,Ni,Rh,和Ru。涉及CO解离和氢化的所有相关基本步骤及其对表面结构的依赖性,表面覆盖率,温度,并考虑了压力。还探索了费托合成的主要机理,包括对H辅助CO解离和直接CO解离结构的敏感性。低配位的步骤位点显示出增强催化活性并抑制甲烷形成。氢吸附和CO解离机制高度依赖于表面覆盖率,其中氢吸附增加,在高覆盖率下,CO插入机制变得更加有利。结果表明,链增长概率和产物选择性受催化剂类型及其结构以及施加的温度和压力的影响。