摘要
CO_(2)催化加氢资源化利用对于实现“双碳”战略目标具有重要的意义,开发丰产绿色高效的连续化反应催化剂仍是当前的研究重点。Mo_(2)C基催化剂在加氢反应中表现出类贵金属的性质,具有较好的催化活性和选择性,但传统Mo_(2)C基催化剂存在比表面积小、Mo_(2)C分散性差、强度低等问题,继而其连续化催化性能仍有待提升。本研究采用椰壳基介孔活性炭作为复合金属的载体和金属碳化物的碳源,有效提升了催化剂的比表面积和强度,利于活性位点的均匀分散。通过一步共浸渍法和还原渗碳反应,制备了具有优良催化活性、选择性和稳定性的工业级Cu-Mo_(2)C/介孔炭催化剂。探究了渗碳温度和铜负载量对Mo_(2)C和Cu在介孔炭表面的分散生长机制及其相互作用规律。通过表征测试,阐明了Cu-Mo_(2)C/介孔炭的结构性质与CO_(2)常压加氢制备CO性能之间的构效关系。在常压、CO_(2)与H_(2)体积比为1∶2、体积空速为60000 mL/(g•h)、温度为500℃的条件下,CO_(2)转化率达36.11%,CO选择性为100%,介孔颗粒炭催化剂可稳定运行40 h以上。本研究为CO_(2)连续催化转化制备低碳化学品提供了新的研究思路和技术理论。
The strategic goal of“double carbon”necessitates the resource utilization of CO_(2) catalytic hydrogenation.The reverse water-gas shift reaction is one of the most promising methods for large-scale CO_(2) conversion with good selectivity and low operating pressure,in contrast to the high-pressure conversion processes like CO_(2) to methanol.Currently,research is concentrated on developing catalysts for continuous reactions that are extremely productive,ecologically friendly,and effective.Mo_(2)C-based catalysts have excellent catalytic performance in hydrogenation reactions and noble metal-like properties,but traditional Mo_(2)C-based catalysts have low specific surface area,large particle size,low strength,and poor activity,all of which severely affect their catalytic performance.In this study,the mesoporous activated carbon derived from coconut shells serves as both a carbon source and a carrier of carbon,and thanks to its high thermochemical stability,it can prevent the formation of polymerized carbon coke,which would otherwise block the pore channels and cover the active center.It also has the benefits of a large specific surface area,easily adjustable pore size distribution and surface groups,adjustable strength,controllable surface metal distribution,which effectively promote the uniform dispersion of active sites.The currently available Mo_(2)C composite catalysts are typically fabricated using the reductive carburization process in a hydrogen environment by means of transition metal oxides as precursors and low-carbon gases like CH_(4) and CO as carbon sources.However,the low-temperature pyrolysis of low-carbon gases would result in the production of coke,which would be deposited on the surface of the carbide.The catalyst strength is also low and requires high pressure molding before it can be applied to continuous fixed bed reactions.In this study,the industrial grade Cu-Mo_(2)C/mesoporous carbon catalysts with excellent catalytic activity,selectivity and stability were prepared by the one-step co-im
作者
潘雪媛
孙昊
王奎
蒋剑春
PAN Xueyuan;SUN Hao;WANG Kui;JIANG Jianchun(Institute of Chemical Industry of Forest Products,Chinese Academy of Forestry,Nanjing 210042,China)
出处
《林业工程学报》
CSCD
北大核心
2022年第6期86-92,共7页
Journal of Forestry Engineering
基金
国家自然科学基金(32101474)。
关键词
逆水煤气反应
CO_(2)加氢
铜-碳化钼
介孔炭
渗碳
reversed water-gas shift reaction
CO_(2)hydrogenation
Cu-Mo_(2)C
mesoporous carbon
carburization
