直接甲酸燃料电池Pt基和Pd基阳极催化剂的理论模拟与设计

Direct formic acid fuel cells (DFAFCs) are known as one of viable power sources with potential applications in many systems, so developing the Pt- and Pd-based anode catalysts that are of excellent catalytic activity, good stability and improved tolerance towards CO-poisoning is becoming great demand in the study of DFAFCs. The item aims to elucidate the catalytic mechanism and structure-activity relationship of Pt- and Pd-based bimetallic catalysts at atomic and molecular level. Based on the calculations of first-principles, molecular dynamics (MD) and surface-enhanced raman spectroscopy (SERS), we clarify the microstructure of Pt- and Pd-based bimetallic catalysts and the adsorption geometry of intermediates on catalysts during HCOOH electrooxidation and elucidate the relationship between structure and surface-enhanced raman spectroscopy in order to compare with experiments. Furthermore, we investigate the molecular mechanism of HCOOH electrooxidation on catalysts and analyze the reaction thermodynamic and dynamical properties so as to improve the theoretical models of HCOOH electrooxidation. Moreover, based on the results of analyzing the energy band, density of states, charge and orbit, we obtain the microscopic nature of synergistic mechanism on Pt- and Pd-based bimetallic catalysts and the key factors controlling the catalytic activity. Finally, we screen out a series of new and efficient Pt- and Pd-based bimetallic catalysts, which would provide the mechanism guidance and theoretical basis for the rational design of new and efficient Pt- and Pd-based anode bimetallic catalysts of DFAFCs.

直接甲酸燃料电池（DFAFCs）被认为是最有应用前景的新型能源系统之一，发展对甲酸电氧化催化活性好、稳定性高、抗中毒能力强的新型Pt与Pd基阳极催化剂是DFAFCs研究的一个重大需求。本项目着眼于从原子分子微观层次研究Pt基和Pd基双金属催化剂的催化机理及构效关系，通过量子化学第一性原理计算、分子动力学演化和表面增强拉曼光谱的模拟，弄清Pt基和Pd基双金属催化剂的微观结构以及催化甲酸电氧化的中间体的吸附构型，并且阐明结构与表面增强拉曼光谱的关系，与实验建立联系，进一步探讨甲酸电氧化的分子机理，分析反应的热力学和动力学性质，从而完善甲酸电氧化的理论模型，最后分析催化剂的能带、态密度、电荷和轨道等信息，掌握双金属催化剂催化增效机制的微观本质和控制催化剂活性的关键因素，最终筛选出一些性能优良的新型Pt与Pd基双金属催化剂，为新型高效的DFAFCs阳极催化剂的开发和设计提供机理指导与理论依据。

直接甲酸燃料电池(DFAFCs)被认为是最有应用前景的新型能源系统之一，发展对甲酸电氧化催化活性好、稳定性高、抗中毒能力强的新型Pt基和Pd基阳极催化剂是DFAFCs研究的一个重大需求。本项目着眼于从原子分子微观层次研究Pt基和Pd基双金属催化剂的催化机理及构效关系，通过第一性原理计算和分子动力学演化的模拟，弄清Pt基和Pd基双金属催化剂的微观结构以及催化甲酸电氧化的中间体的吸附构型，进一步探讨甲酸电氧化的分子机理，分析反应的热力学和动力学性质，从而完善甲酸电氧化的理论模型，最后分析催化剂的功函数、态密度和电荷等信息，掌握双金属催化剂增效机制的微观本质和控制催化剂活性的关键因素，最终筛选出一些性能优良的新型Pt基和Pd基双金属催化剂，为新型高效的DFAFCs阳极催化剂的开发和设计提供机理指导和理论依据。.公认的甲酸被氧化成CO2通过三条路径进行：直接路径，间接路径和甲酸盐路径，根据甲酸分子之间形成的氢键，我们通过第一性原理计算，提出并完善了甲酸氧化的二聚体路径，解释了不同甲酸氧化实验中发现的有争议的CO形成机理和中间体，并且设计出新型高效的PtAu双金属催化剂，进一步通过甲酸水溶液中的分子动力学计算，建立并完善了甲酸的二聚体模型。根据甲酸氧化的团簇效应，进而研究了甲醇与氧气反应的耦合效应、羟基协助的氧气活化反应和水协助的析氧反应等，通过分析极化电荷、功函数和态密度，找出催化反应的活性点以及增效机制。