摘要
一氧化碳/二氧化碳(CO/CO_2)转化利用是碳一化学与CO_2捕集利用中的重要环节,也是当今碳资源的非石油路线利用最具挑战性的方向之一。CO_2的高效活化与定向转化是CO_2利用过程中的关键问题,而CO加氢转化最大的瓶颈问题为如何有效控制C-O键的活化、C—C键的形成、碳链增长及终止。本文主要综述CO/CO_2加氢高选择性合成重要化工原料低碳烯烃(C2=～C4=)以及一步高效合成汽油馏分(C5～C11)等方面取得的突破性进展。目前,CO/CO_2加氢主要经过费托合成与氧化物/分子筛双功能两条路线合成低碳烯烃与汽油燃料。针对费托合成C2=～C4=,分析表明棱柱状碳化钴得到的烃类产物分布可以显著突破Anderson-Schulz-Flory (ASF)分布的限制,而分子筛已被广泛用于构建双功能费托催化剂,由于酸性分子筛具有加氢裂化、低聚与异构化等功能,使得CO/CO_2还可以直接高选择性地转化为C5～C11烃类。另一方面,将可以活化CO或CO_2到甲醇的可还原型氧化物与具有C—C偶联功能的SAPO-34或HZSM-5分子筛进行耦合,也可以实现CO/CO_2加氢一步合成低碳烯烃或汽油且具有非常优异的选择性和高转化率。今后,借鉴纳米合成领域新方法,使产物分布打破经典ASF限制,最大限度地提高目标烃类化合物的选择性并显著减少甲烷的生成是研究关键。
Carbon monoxide/carbon dioxide(CO/CO2)utilization,as the central part of C1 chemistry and carbon capture and utilization,becomes one of the most severe challenges for human society nowadays.For CO2 utilization,it is very important to achieve CO2 activation and C-C precise coupling simultaneously.It is a great challenge to control C-O activation,C-C coupling carbon chain growth and termination effectively for syngas conversion.We provide an overview of the significant breakthrough on CO/CO2 hydrogenation to lower olefins(C2=-C4=),which are widely used in the chemical industry and direct CO2 hydrogenation to gasoline-range hydrocarbons(C5-C11)with high selectivity.Currently,Fischer-Tropsch(FT)synthesis and oxide/zeolite bifunctional catalysis routes can be utilized to produce lower olefins or gasoline fuels directly from CO/CO2 hydrogenation.For FT to C2=-C4=,the product distribution over cobalt carbide nanoprisms deviates markedly from the classical Anderson-Schulz-Flory(ASF)distribution.In addition,acidic zeolites have been exploited to construct the bifunctional FT catalyst,and CO/CO2 can be directly transformed into C5-C11 hydrocarbons with good selectivity owing to the catalytic function of acidic zeolite in the hydrocracking/oligomerization/isomerization reactions.On the other hand,the integration of the reduced oxide,which is responsible for the activation of CO or CO2 to methanol,and SAPO-34 or HZSM-5 zeolite responsible for the selective C-C coupling can also realize the direct synthesis of lower olefins or gasolines from CO/CO2 hydrogenation with excellent selectivity at a high conversion.In the future,the main objective is to maximize the selectivity of the target hydrocarbons and to reduce methane production significantly by adopting new methods in nano-synthetic areas which deviates from the classical ASF distribution.
作者
高鹏
崔勖
钟良枢
孙予罕
GAO Peng;CUI Xu;ZHONG Liangshu;SUN Yuhan(CAS Key Lab of Low-Carbon Conversion Science and Engineering,Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;University of the Chinese Academy of Sciences, Beijing 100049, China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2019年第1期183-195,共13页
Chemical Industry and Engineering Progress
基金
国家自然科学基金(21773286
21503260)
中国科学院青年创新促进会项目(2018330)
中国科学院洁净能源先导科技专项(XDA21090204)
上海市科学技术委员会项目(16DZ1206900)
关键词
合成气
二氧化碳
加氢
费托合成
分子筛
syngas
carbon dioxide
hydrogenation
Fischer-Tropsch synthesis
moleclar sieves
