Co/ZrO2@碳纳米管催化生物合成气直接制备柴油烃的反应机理研究

生物合成气制备柴油烃是实现生物质转化制液体燃料的路线之一，极具开发潜力。但是，传统费托合成过程中反应物转化率和柴油烃选择性间存在跷跷板效应，难以同步提高。为解决此难题，本项目提出将“金属中心-酸中心”集成的Co/ZrO2@碳纳米管双功能催化剂用于催化生物合成气直接制备柴油烃的新方法，以实现柴油烃选择性的精确调控，达到生物合成气高效转化的目标。首先研究Co-Zr双金属有机框架热解过程参数和后处理方法对催化剂表界面结构及性质的影响规律，实现催化剂表界面结构和性质的精确制备；明确双功能催化剂的构-效关系，阐明费托合成和高碳烃C-C键重构反应的协同耦合机制，揭示催化反应机理；探讨催化剂填充床反应器内流动-传热传质-催化反应之间的耦合协同关系，阐明强化柴油烃选择性的双功能催化位点的靶向调控机制和关键工况参数的控制机制。项目的完成将会丰富生物质经合成气转化制液体燃料的基础理论体系，具有重要的科学意义。

The transformation of bio-syngas into diesel fuel represents a promising pathway for producing liquid biofuel from biomass. However, the traditional Fischer-Tropsch synthesis (FTS) suffers from a see-saw effect between the selectivity of diesel-range hydrocarbons and the conversion ratio of bio-syngas. To overcome the problem, this project proposed an integrated catalytic process for the direct conversion of bio-syngas into diesel-range hydrocarbons over Co/ZrO2@CNTs bifunctional catalysts integrated with a metal center and an acid center, achieving perfect combination of higher selectivity toward diesel-range hydrocarbons and higher conversion of bio-syngas. The research would be performed according to the following steps: 1) to study the synthesis method of Co/ZrO2@CNTs from Co-Zr bimetal-organic frameworks through a low-temperature pyrolysis process, tuning the structure and the property of Co/ZrO2@CNTs by controlling the pyrolysis process and the postprocessing; 2) to identify the structure-function relationship of the bifunctional catalysts, revealing the coupling mechanism between the FTS and the C–C cleavage of heavier hydrocarbons, and the reaction mechanism; 3) to analyze the mechanism of heat and mass transfer coupling with chemical reaction in the reactor packed with Co/ZrO2@CNTs, clarifying the targeting control of bifunctional catalytic site and operating parameter for higher production of diesel fuel. The completion of the project will enrich the basic theoretical system for synthesis of liquid fuel from biomass via bio-syngas, which has an important scientific significance.