水合肼分解制氢催化剂设计、可控合成与催化机理研究

The development of advanced hydrogen storage materials and technologies is a key step towards the widespread implementation of hydrogen fuel cell technology. Recently, hydrous hydrazine has attracted considerable interest as a promising hydrogen storage medium for vehicular and mobile applications. The present project was designed to investigate the catalytic decomposition of hydrous hydrazine for chemical hydrogen storage, with special focues on the fundamental research of the key scientific questions such as catalytic decomposition mechanism of hydrous hydrazine over Ni catalyst, the underlying mechanism of property enhancement arising upon Ni-based alloying. The main research subjects can be summarized as follows: Prepare a series of supported Ni-based alloy nanocatalysts using chemical synthesis methods and investigate the effects of preparation conditions on the catalyst composition, phase structure, microstructure and morphology, distribution state of alloy element and surface electronic structure; Develop novel technologies for controllable synthesis of targeted catalyst with tailored structure and tuned catalytic properties; Theoretically study the adsorption state and dissociation process of the N2H4 molecular on the surface of Ni-based catalysts, and bring forward a theoretical model of the catalytic decomposition of hydrous hydrazine over Ni catalyst; Investigate the composition-structure-property correlationship and put forward the basis and principle for composition/structure design of high-performance catalysts; Development of hydrous hydrazine-based chemical hydrogen storage systems and study of catalytic decomposition kinetics. The present project may contribute to the theoretical enrichement and development of on-demand hydrogen generation from hydrous hydrazine, and lay key foundation for the developement of practical chemical hydrogen storage systems.

发展先进的储氢材料与技术是推动氢燃料电池技术实用化进程中的关键环节。本项目选取水合肼催化分解制氢这一颇具车载/移动氢源应用潜力的化学储氢体系为研究对象，重点围绕Ni催化水合肼分解反应机理、Ni基催化剂的合金化改性机理等关键基础科学问题开展实验/理论研究。拟采用化学合成方法制备系列负载型Ni基合金催化剂，研究制备条件对催化剂成分、晶相组成、微观结构与形貌、合金原子分布及表面电子结构的影响规律，探索目标催化剂可控合成技术；模拟计算研究N2H4分子在Ni基催化剂表面吸附、解离路径及其动力学过程，建立Ni催化水合肼分解的理论模型；解析催化剂成分-结构-催化性能的内在关联，建立催化剂成分/结构优化设计原则；结合实验与模型分析，研究水合肼催化分解反应动力学规律。本项目研究将丰富与发展水合肼催化分解制氢的基础理论，为研发实用型化学储氢系统奠定实验与理论基础。

发展先进的储氢材料与技术是推动氢能技术实用化进程中的关键环节。本项目选取水合肼催化分解制氢体系为研究对象，重点围绕水合肼催化分解机理、Ni基催化剂的合金化改性机理等关键基础科学问题开展研究。项目的主要研究内容包括：（1）运用第一性原理计算研究水合肼的催化分解反应机理，探究水合肼分解催化剂的成分优化设计原则；（2）探索水合肼分解催化剂的改性新方法，研究催化剂成分-结构-催化性能的内在关联性；（3）构建水合肼可控催化放氢体系，研究水合肼催化放氢动力学性能。本项目在执行期内取得以下主要成果：（1）首次完整解析了Ni催化N2H4分解的机制过程；率先提出了以N2H4吸附能作为催化活性描述符的观点，从理论角度提供了肼分解催化剂的筛选依据；（2）结合运用合金化、异质原子掺杂、纳米结构调制等策略，成功研制出数种可在近室温高效催化水合肼分解制氢的Ni基合金催化剂，其中NiPt/NC催化剂可在50 C/2 M NaOH条件下的TOF值达1602 h1，制氢选择性达到100%。（3）应用Ni-W-O衍生的非贵金属催化剂和市售水合肼构建了高容量可控制氢体系，其材料基储氢密度高达6.28 wt%，且具良好的动态响应特性。项目在执行期内发表SCI论文12篇，申报国家发明专利3件；培养博士/硕士研究生6名。项目圆满完成计划任务。本项目研究成果将丰富与发展水合肼催化分解制氢的基础理论，为研发实用型化学储氢系统奠定实验与理论基础。