甲烷二氧化碳重整新结构镍基催化剂的设计及双重限域效应研究

Currently, it is quite urgent to develop low-cost non-noble metal based high-performance catalysts for carbon dioxide reforming of methane to produce the syngas. Nickel-based catalysts have exhibited excellent catalytic activity for carbon dioxide reforming of methane, but one of the major problems over Ni-based catalysts is the deactivation of catalytic performance resulting from the carbon formation and the sintering of the active nickel species. In this proposal, based on the unique characteristics of Layered Double Hydroxides (LDH) and mesoporous oxides, the Ni-based advanced catalysts with dual confinement effects will be designed and fabricated. The catalysts will be evaluated by traditional characterization methods, in-situ analysis as well as surface reaction techniques, and also investigated by catalytic simulations and calculations. The formation mechanism of Ni-based advanced catalysts will be investigated. The surface physicochemical properties as well as compositions and structure of active sites of catalysts will be tuned. The reaction kinetics and diffusion behavior over the catalysts during the catalytic reforming process will be investigated at length. The relationship of active components, morphologies, surface physicochemical properties and coke- and sintering-resistance performance will be established. The adsorption and activation mechanism of the reactants over the catalysts will be deeply investigated. The nature of the active centers as well as geometric and electronic effects will be elucidated. The coke- and sintering-resistance mechanism of the catalysts will be revealed. The synergistic promoting effects of different confinement modules will be clarified. Finally, the internal logics and theoretical models of Ni-based advanced catalysts will be established. This work will provide theoretical guidance for the design of high-performance Ni-based advanced catalysts with dual confinement effects for carbon dioxide reforming of methane. Besides, the research results will also enrich the theory of heterogeneous catalysis.

当前甲烷二氧化碳重整转化制合成气技术迫切需要寻找价格低廉的高性能非贵金属催化剂。针对高活性镍基催化剂易积碳易烧结的难题，本项目拟利用层状双羟基复合金属氢氧化物（LDH）的结构限域效应以及介孔氧化物的孔道限域效应，设计并制备具有双重限域效应的新结构镍基催化剂，采用常规表征手段，结合原位测试、表面反应技术以及催化模拟计算，研究其形成机制，调控其表面物理化学性质以及活性位组成与结构，重点研究其催化重整过程中的反应动力学与扩散行为规律，明确其组分、形貌结构、表面物理化学性质与催化重整过程中抗积碳、抗烧结性能的关系，深入研究反应物在催化剂表面的吸附活化机理，理解其活性中心的本质及几何效应和电子效应的影响，明晰抗积碳和抗烧结的作用机制，揭示催化剂不同限域单元的协同促进作用机理，建立其内在联系和理论模型，为设计具有双重限域效应的高性能镍基甲烷二氧化碳重整催化剂提供理论指导，并藉此丰富多相催化的研究理论。

当前甲烷二氧化碳重整转化制合成气技术迫切需要寻找价格低廉的高性能非贵金属催化剂。针对高活性镍基催化剂易积碳易烧结的难题，本项目利用层状双羟基复合金属氢氧化物以及缺陷氮化硼等特定化合物的结构限域作用以及介孔氧化物的孔道限域作用，设计并发展了一系列新的制备方法，制备了具有结构限域效应、介孔限域效应以及双重限域效应的新结构镍基催化剂，采用SEM、TEM、ICP、XRD、XPS、BET、TPR、TG-DTA等对催化剂进行常规表征，结合原位漫反射红外测试技术、表面反应技术以及量化计算，研究了其形成机制，调控了其表面物理化学性质以及活性位组成与结构，重点研究了其催化重整过程中的反应动力学与扩散行为规律，明确了其组分、形貌结构、表面物理化学性质与催化重整过程中抗积碳、抗烧结性能的关系，深入研究了反应物在催化剂表面的吸附活化机理，理解了其活性中心的本质及几何效应和电子效应的影响，明晰了抗积碳和抗烧结的作用机制，揭示了催化剂不同限域单元的协同促进作用机理，建立了其内在联系和理论模型。研究结果显示，利用新结构镍基催化剂的双重限域效应可以有效解决其活性组分烧结以及表面积碳的难题，所得催化剂的活性和稳定性得到了极大改善。本项目发表10篇SCI论文，其中2篇论文成为ESI高被引论文；申请国家发明专利5项，其中2项已获授权。本项目的成功实施，为设计高性能镍基甲烷二氧化碳重整催化剂提供了理论指导，并藉此丰富了多相催化的研究理论。