生物油催化重整制氢反应活性-积碳-烧结耦合机理定量研究

Renewable bio-oil, which has complex composition and low heat value, can be converted into clean and high value hydrogen through catalytic reforming technology. However, the mechanism is yet unclear and the rapid deactivation of catalyst is always caused by coking and sintering, which dominantly limits the industrial application of the catalytic reforming technology. It has become one of the research focuses and theoretical difficulties in the relevant field.. This project intends to conduct quantitative studies on the activity-coking-sintering coupling mechanism of bio-oil catalytic reforming for hydrogen production by correlating experimental research and molecular simulation. Experimental research on catalytic reforming of bio-oil model compounds, combined with catalyst characterization, will be initially carried out to establish the structure-activity relationship and to select the efficient catalyst with superior anti-coking and anti-sintering capacity. Subsequently, over the selected catalyst, quantitative calculations on transition state, rate constant of catalytic reforming reaction and electron structure of the catalyst will be conducted through density functional theory. Reaction pathways as well as coke formation mechanism will be constructed, and minimum energy reaction route will also be determined. Meantime, catalyst's sintering kinetics under high steam partial pressure and high temperature conditions will be obtained via molecular dynamics simulation. The mechanism model will be improved by further studies on catalytic reforming of crude bio-oil and the mixture of bio-oil model compounds. In general, carrying out this project will help to improve the understanding of the mechanism of bio-oil catalytic reforming reaction, and it will also help to complete the relevant bio-oil catalytic upgrading theory system.

通过催化重整技术可以将成分复杂低热值的可再生生物油转化为清洁高效的氢气，然而反应机理不清晰以及积碳与烧结导致的催化剂快速失活成为限制其工业应用的关键问题，近年来逐渐成为该领域的研究热点与理论难点。. 本项目拟通过实验研究和分子模拟定量计算相结合，开展生物油催化重整制氢反应活性-积碳-烧结耦合机理研究。首先通过生物油模化物开展催化重整制氢试验研究，结合催化剂表征，建立催化剂结构与活性之间的构效关系，筛选抗积碳抗烧结高效催化剂。然后利用密度泛函理论在高效催化剂上开展反应过渡态、化学反应速率常数和催化剂电子结构定量计算，构建催化重整反应路径与积碳生成机理，确定反应的最小能量路径。同时通过分子动力学模拟，获得催化剂在高温高水蒸汽分压下的烧结动力学规律。随后进一步结合真实生物油、模化物混合配比的实验研究，精修理论模型。通过本项目的研究，有助于明晰相关反应机理，完善生物油催化提质理论体系。

生物油催化重整制氢是一项非常有潜力的生物质能利用技术。本项目系统开展了生物油催化重整制氢反应机理的密度泛函理论计算，选取生物油典型模化物乙酸、甲酸，构建了乙酸、甲酸分解基元反应网络，定量获得了各步基元反应活化能和反应焓数据，计算得到了各步反应的速率常数与平衡常数；得到了反应中间体以及各个基元反应初终态、过渡态的吸附构型，构建了乙酸、甲酸分解反应势能面；并通过微观动力学模拟，成功预测了分解过程中产物分布情况，获得了反应进行的最小能量路径。此外，获得了关键焦炭前驱体丙酮和CH的生成与演变规律。掌握了溶剂水、甲醇和丙酮对反应中间体吸附、反应的影响规律。开展了生物油模化物C1-C4羧酸在分子筛催化剂内吸附研究，揭示了分子筛吸附时范德华力的重要作用，发现溶剂效应对分子筛吸附具有较大的影响。同时搭建了生物油催化重整微反试验台，开展了相关的实验研究。相关研究有效完善了生物油催化重整制氢理论体系。以第一作者身份发表了5篇高质量SCI论文及申报了1项发明专利，培养在读硕士生1名，指导1名本科毕业生获得校级优秀毕业论文。