摘要
CO_(2)甲烷化技术不仅可以实现CO_(2)的循环利用,还能解决CO_(2)排放带来的环境问题。近年来,Ni基催化剂因催化活性好、甲烷选择性高和价格低廉等优点被广泛应用于CO_(2)甲烷化反应中。重点阐述了Ni颗粒的尺寸效应、表面微细结构、载体种类及物理化学性质(碱性位、氧空位、比表面积、孔结构和金属-载体间相互作用)对CO_(2)甲烷化催化剂催化性能的影响,介绍了Ni基双金属合金、结构和电子型助剂对其催化性能的影响,归纳了不同催化剂上CO_(2)甲烷化机理,剖析了Ni基催化剂失活的原因,论述了Ni基催化剂在光热催化CO_(2)甲烷化中的应用,最后对CO_(2)甲烷化催化剂未来研究方向进行了展望。通过对比不同体系获得的研究结果发现,CO_(2)甲烷化反应为结构敏感性反应,Ni颗粒尺寸对催化剂活性有显著影响,然而不同研究得出的最佳Ni颗粒尺寸有明显差异,这可能与不同金属与载体间相互作用或不同制备方法导致的Ni颗粒表面微细结构(如不同晶面、缺陷位等)差异有关,Ni颗粒的尺寸效应有待深入研究;第二金属的加入形成Ni基双金属合金、助剂及研究金属-载体相互作用都有助于开发高稳定性的催化剂;载体表面丰富的碱性位及氧空位,有利于CO_(2)吸附与活化,进而提高催化剂活性。目前,CO_(2)甲烷化反应路径主要分为CO路径和甲酸盐路径,反应遵循的路径可能与反应条件(如温度、压力等)及催化剂表面性质(如羟基丰富度、O^(2-)吸附位点等)有关。然而,关于助剂或载体与Ni物种间的纳米界面结构,以及采用不同助剂和载体对催化剂活性位点及CO_(2)甲烷化反应路径的影响机制,尚缺乏较深入的认知。因此,需借助现场原位成像技术及光谱学技术对催化剂的表界面几何与电子结构进行精细、动态的结构剖析,建立动态结构与性能的构效关系,有利于指导设计合成特定结构的�
Carbon dioxide methanation is a promising technology for realizing the recycling of CO_(2) and solving the environmental problems caused by CO_(2) emissions.Ni-based catalysts have been widely used in CO_(2) methanation in recent years because of their good catalytic ac.tivity,high CH_(4) selectivity,and low price.The effects of Ni particle size effect,surface microstructure,support type and physicochemical properties(alkaline site,oxygen vacancy,specific surface area,pore structure and metal support interaction)on the catalytic performance of CO_(2) methanation catalyst were emphatically described.The effects of Ni-based bimetallic alloy,structure and electronic additives on its catalytic performance were introduced,the CO_(2) methanation mechanism on different catalysts were summarized,the reasons for the deacti.vation of Ni based catalysts were analyzed,and the application of Ni-based catalysts in photothermal catalytic CO_(2) methanation was dis.cussed.Finally,the future research direction of CO_(2) methanation catalyst has been prospected.By comparing the results of different sys.tems,it reveals that the CO_(2) methanation is a structure-sensitive reaction,in which Ni particle size has significant effect on the activity of the catalysts.However,the optimum Ni particle sizes obtained by different studies are various,which may be related to the difference of the surface microstructure(such as different crystal planes,defect sites,etc.)of Ni particles caused by the different interaction between metals and carriers or preparation methods.Thus,the size effect of Ni particles remains to be further studied.Moreover,the activity and stability of the Ni catalysts can also be improved by adding the second metal or promoters,or tuning the interaction between Ni particles and carriers.The abundant alkaline sites and oxygen vacancies on the surface of the support are conducive to CO_(2) adsorption and activation,so as to im.prove the activity of the catalyst.At present,the proposed mechanisms of CO_(2) methanation over N
作者
张晓俐
古芳娜
苏发兵
许光文
ZHANG Xiaoli;GU Fangna;SU Fangbing;XU Guangwen(Key Laboratory on Resources Chemicals and Materials of Ministry Education,Shenyang University of Chemical Technology,Shenyang 110142,China;State Key Laboratory of Multiphase Complex Systems,Institute of process Engineering,Chinese Academy of Sciences,Beijing 100190,China;Institute of Industrial Chemistry and Energy Technology,Shenyang University of Chemical Technology,Shenyang 110142,China)
出处
《洁净煤技术》
CAS
北大核心
2022年第4期1-17,共17页
Clean Coal Technology
基金
国家自然科学基金资助项目(21776286)。
关键词
CO_(2)甲烷化
镍基催化剂
光热催化
第二金属
载体
催化活性
carbon dioxide methanation
nickel-based catalyst
photothermal catalysis
second metal
support
catalytic activity
