负载型Pd-Cu低氢还原水中硝酸盐反应速率和氮气选择性同步调控原理研究

近年来，我国水体中总氮总量控制一再收紧，而NO3-去除是总氮控制的关键环节。Pd-Cu/载体催化还原法是最有效的NO3-去除法之一，但存在NO3-反应速率和N2选择性不同步的问题。基于此，本项目将以原位电解水制备的H2为还原剂，γ-Al2O3和β-沸石为载体，研究Pd-Cu/载体还原NO3-反应速率和N2选择性的同步调控原理。结合实验和DFT计算，首先通过调变载体织构和表面酸碱度，明确其电子结构与Pd-Cu分散度的内在关系，以及载体与Pd-Cu的电子相互作用；深入研究载体与Pd-Cu的协同作用，阐明Pd-Cu/载体影响NO3-去除速率和N2选择性的机理；进一步揭示水环境因子，包括pH、DO和阴离子等对Pd-Cu/载体还原NO3-性能的影响机制，优化Pd-Cu/载体催化体系。最终实现Pd-Cu/载体还原NO3-反应速率和N2选择性的同步高效调控，为筛选NO3-催化还原体系提供坚实的理论基础。

Recently, the discharge control of total nitrogen is becoming more and more strict in lakes in China. NO3- removal is the key problem in the decrease of the total nitrogen content. Supported Pd-Cu bimetal is one of the best effective catalysts for NO3- reduction. The greatest challenge is accelerating the reaction rate and increasing the selectivity of N2 at the same time. Based on above mentioned, this program is designed. Using in-situ generated H2 as reductant，γ-Al2O3 and β-zeolite as supports, the synchronous control principle of reduction rates and nitrogen selectivity of nitrate by Pd-Cu/support will be studied. In this work, experiments combined with DFT calculations will be used. Firstly, we will investigate the methods that can change acidity and basicity, as well as the texture of γ-Al2O3 and β-zeolite. Then, the intrinsic relationships between their electronic distribution and Pd-Cu dispersion will be established. Furthermore, the synergistic effect of Pd-Cu catalyst and supports will be probed. Based on these, the mechanisms of Pd-Cu/supports on NO3- reaction rates and N2 selectivity will be elucidated. Lastly, the effects of water qualities, including pH, dissolved oxygen, and anions on NO3- reaction rates and N2 selectivity will be analyzed. This study will propose a theory of synchro and effective control on NO3- reaction rates and N2 selectivity by Pd-Cu/supports and shed a light on screening effective catalysts for NO3- reduction.