摘要
二氧化碳甲烷化技术被认为是二氧化碳循环再利用最有效的技术之一。目前关于二氧化碳甲烷化的反应机理尚无统一认识,所提出的反应机理主要有三个：一氧化碳中间态机理、含氧酸根中间态机理和二氧化碳直接加氢机理。选取具有较高催化活性且同时具备优良选择性的催化剂对二氧化碳甲烷化反应至关重要,目前主要为Ⅷ族金属（Ni、Co、Rh、Ru和Pd）催化剂,该族金属催化剂表现出较好的催化性能。就二氧化碳甲烷化反应的工业化催化剂而言,活性组分应以镍为主,以稀土元素为改性组分;催化剂载体应以氧化铝载体为主要方向,并添加热稳定性高的组分以提高载体的热稳定性;在催化剂制备中要控制催化剂的孔道结构和表面酸碱性,以降低表面积碳的速率。开发综合性能优异的复合氧化物载体及其负载的镍基催化剂,应该是二氧化碳甲烷化催化剂的发展方向。早期二氧化碳甲烷化反应是通过外部引入热源对二氧化碳分子进行活化,最终越过能垒获得甲烷分子。随着研究的不断深入,学者们发现利用电催化和光催化的方法同样能使反应分子活化,而且还具有环境友好和绿色安全等优点,在工业化方面显示出一定潜力。充分利用太阳能以实现二氧化碳资源的循环利用,也是二氧化碳甲烷化的研究方向。
Technology for methanation of carbon dioxide is considered as one of the most effective technologies for carbon dioxide recycling.At present,there is no consensus on the reaction mechanism of methanation of carbon dioxide.The three main reaction mechanisms include the intermediate state of carbon monoxide,the intermediate state of oxoacid and the direct hydrogenation of carbon dioxide.Selecting catalysts with high catalyt-ic activity and excellent selectivity are important for the methanation of carbon dioxide.Currently,group VIII metal（Ni,Co,Rh,Ru and Pd） catalysts,which show good catalytic performance,are mainly used.The industrial catalyst for methanation of carbon dioxide should take nickel as the main active component and rare earth el-ement as the modified component.The catalyst support should mainly use alumina support and add components with high thermal stability to increase the thermal stability of the support.The pore structure and surface acid-ity and basicity of the catalyst should be controlled during the preparation of catalyst to reduce the rate of surface carbon deposition.The development of composite oxide supports with excellent comprehensive perfor-mance and the supported nickel-based catalysts should be the development direction of the catalyst for carbon dioxide methanation.In the early stage,the carbon dioxide methanation reaction was carried out by externally introducing a heat source to activate the carbon dioxide molecules to pass over the energy barrier and obtain methane molecules.With the deepening of research,scholars found that electrocatalysis and photocatalysis can also activate the reaction molecules and has the advantages of environmental friendliness and green safety,showing potential in industrialization.Making full use of solar energy to achieve the recycling of carbon dioxide resources is also a research direction of the methanation of carbon dioxide.
作者
史建公
刘志坚
刘春生
Shi Jiangong;Liu Zhijian;Liu Chunsheng(Engineering Technology Research Institute of SINOPEC Catalyst Co.,Ltd.,Beijing 101111;SINOPEC Catalyst Co.,Ltd.,Beijing 100029;Sino-Global Energy,Beijing 100011)
出处
《中外能源》
CAS
2018年第10期70-87,共18页
Sino-Global Energy
关键词
二氧化碳
甲烷化
反应机理
镍基催化剂
复合氧化物载体
光电催化
carbon dioxide
methanation
reaction mechanism
nickel-based catalyst
composite oxide support
elec trocatalysis and photocatalysis
