镶嵌型钯合金@氮化碳催化剂的精准构筑及其催化甲酸脱氢性能研究

甲酸是最具潜力的化学储氢材料之一，脱氢反应是制约其大规模应用的主要瓶颈，构建合理的活性中心分布方式（催化剂结构）是改善此类反应选择性和稳定性不理想的关键。本项目针对现有催化剂活性组分颗粒分布不均、易流失和团聚的问题，拟在前期工作的基础上，提出精准构筑镶嵌型钯合金@氮化碳催化剂的新思路，利用镶嵌型催化剂的合金效应和镶嵌效应的优点，以改善催化剂的选择性和稳定性。探索金属类型、含氮前驱体种类等制备条件对催化剂结构的影响，阐明以多孔材料为模板剂的镶嵌型催化剂的合成机制，实现催化剂的可控制备。在此基础上，研究钯合金结构、镶嵌程度和镶嵌层组成等因素对甲酸脱氢反应的影响规律，利用原位技术、理论计算揭示反应机理与催化性能之间的内在联系，阐明钯合金与镶嵌层在甲酸脱氢反应中的协同作用机制，为催化剂的优化构建提供指导。本项目的实施将为贵金属催化剂的构建提供一条新思路，同时也为氢能源大规模应用提供技术支撑。

Formic acid is one of the most promising chemical hydrogen storage materials. Nevertheless, the dehydrogenation of formic acid is the main bottleneck restricting its large-scale application. The key to improve the unsatisfactory selectivity and stability in this process is to construct the reasonable distribution of active sites (catalyst structure). In view of the problem of uneven distribution, easy loss and agglomeration of active component in the existing catalysts, palladium alloy@carbon nitride catalysts with mosaic structure are precisely constructed on the basis of the previous work and aim at enhancing the selectivity and stability by using the advantages of alloy effect and mosaic effect. Through exploring the influence of metal types, nitrogen-containing precursor types and preparation conditions on the structure of the catalyst, the synthesis mechanism of the mosaic catalyst using porous materials as the template is clarified and the controllable preparation of the catalyst can be realized. Accordingly, the influence of factors, such as the palladium alloy structure, mosaic degree and mosaic layer composition, on the dehydrogenation of formic acid are studied. In-situ technology and theoretical calculations are employed to reveal the internal connection between the reaction mechanism and the catalytic performance, and the synergistic mechanism of the palladium alloy and the mosaic layer in the dehydrogenation of formic acid is clarified. This will offer the guidance for the optimization and construction of the catalyst. The success of the above mentioned research will not only present a novel method for the construction of noble metal catalysts, but also provide technical support for the large-scale application of hydrogen energy.