Ni-Fe@碳纳米管/多孔碳催化剂协同强化焦油裂解及调控碳沉积机理研究

Biomass gasification is an important technology for the utilization of biomass resources. However, there are some obstacles such as low tar removal efficiency and catalyst deactivation. In view of this, the directional construction of Ni-Fe@carbon nanotubes/porous carbon catalyst to strengthen tar cracking and synergistically convert carbon deposition into carbon nanotubes for secondary application is studied in this project. Modern characterization techniques and small scale experiments combined with theoretical analysis are used to analyze the evolution and formation mechanism of catalyst. The reaction mechanism of functional groups and molecular fragments during the process of tar catalytic cracking is explored. The relationship between the reaction conditions of tar catalytic cracking process and the carbon deposition of catalyst is disclosed. Regulation method of converting carbon deposition into carbon nanotubes is formulated. The structure-activity relationship of the catalyst is explored, and the synergistic mechanism on strengthening tar cracking and regulating carbon deposition by Ni-Fe@carbon nanotubes/porous carbon catalyst is further revealed. From the experimental and theoretical perspectives, the feasibility of Ni-Fe@carbon nanotubes/porous carbon catalyst for strengthening tar cracking and synergistically converting carbon deposition into carbon nanotubes is analyzed, and its inherent scientific mechanism is also revealed. The research results are expected to establish the theory foundation of catalyst construction and carbon deposition regulation mechanism for the catalytic cracking of biomass tar, and provide scientific reference for the design and preparation of catalyst for tar catalytic cracking.

生物质气化是生物质资源化利用的一项重要技术，但目前仍存在焦油去除效率低且催化剂易积碳失活等问题。鉴于此，本项目提出通过催化剂定向构筑，以强化焦油裂解协同将积碳转变为碳纳米管以便二次应用为目的，设计出Ni-Fe@碳纳米管/多孔碳催化剂，利用现代表征技术和小试实验并结合理论分析解析其形成演化机制，研究催化剂强化焦油裂解过程官能团和分子碎片的反应机制，揭示焦油催化裂解过程反应条件与催化剂积碳形态的内在关系，掌握碳沉积转变为碳纳米管过程调控方法，并探究催化剂的构效关系，进一步揭示催化剂对强化焦油裂解与调控碳沉积的协同作用机制。从实验和理论两个角度，分析Ni-Fe@碳纳米管/多孔碳催化剂强化焦油裂解协同将积碳转变为碳纳米管的可行性，揭示其内在科学机制，研究成果有望构建生物质焦油催化裂解过程中催化剂构筑和积碳调控机制方面的理论基础，为焦油裂解催化剂的设计与制备提供科学参考。

生物质气化是生物质资源化利用的一项重要技术，但目前仍存在焦油去除效率低且催化剂易积碳失活等瓶颈问题。鉴于此，本研究提出了通过特征催化剂的定向构筑，以强化焦油裂解协同将积碳转变为碳纳米管以便二次应用为目的，通过生物质原位碳热还原设计出一系列的Ni-Fe@碳基复合结构催化剂（Ni@碳纳米纤维/多孔碳催化剂、Ni-Fe@碳纳米纤维/多孔碳催化剂和Fe@碳纳米纤维/石墨烯碳壳催化剂），利用现代表征技术和小试实验并结合理论分析解析了其形成演化机制，同时通过两段式固定床催化裂解实验，发现三种碳基纳米金属催化剂的焦油催化裂解去除率均大于90％，且在循环过程中呈现较好的催化稳定性。基于对催化过程的细致分析，研究了催化剂强化焦油裂解过程的反应机制，揭示了焦油催化裂解过程反应条件与催化剂积碳形态的内在关系，并通过在焦油催化过程引入多氢源掌握了碳沉积转变为碳纳米管过程的调控方法，进一步阐述了引入多氢源作用下催化剂对强化焦油裂解与调控碳沉积的协同作用机制。本研究为焦油催化裂解过程催化剂积碳的问题提出了一种新的思路，即是能够通过催化剂的定向构筑和多氢源引入等技术手段，在强化焦油裂解的同时调控催化剂积碳的理化特性，将其转化为高附加值的碳材料（碳纳米管）。研究成果一定程度上构建了生物质焦油催化裂解过程中催化剂构筑和积碳调控机制方面的理论基础，为焦油裂解催化剂的设计与制备提供了科学参考。依托本项目，以第一/通讯作者发表论文23篇（其中SCI/EI论文22篇，中文EI论文1篇，JCR一区论文18篇，影响因子大于10的6篇），并申请国家专利5项。