金红石型氧化物负载的Ir基催化剂应用于绿色推进剂N2O分解反应

项目名称： 金红石型氧化物负载的Ir基催化剂应用于绿色推进剂N2O分解反应

项目编号： No.21476226

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 有机化学

项目作者： 黄延强

作者单位： 中国科学院大连化学物理研究所

项目金额： 80万元

中文摘要： N2O是一种新兴的绿色推进剂，因其独特的优越性能在航天领域受到高度重视。贵金属Ir催化剂是N2O推进剂催化分解的首选，但活性中心IrO2在高温氧化气氛下会因烧结、挥发而失效。本申请采用与IrO2同为金红石晶型的TiO2、SnO2等为载体，利用其晶格相近的特点形成外延生长式结构来稳定IrO2。该申请将系统研究载体晶型、组成、表面积以及预处理条件等因素对IrO2稳定性能的影响规律，探索金红石型氧化物载体对IrO2的稳定机制；采用高分辨透射电镜与X射线能谱技术相结合的手段研究催化剂的微观结构特征，并结合XPS、EPR、微量吸附量热等手段研究催化剂与氧物种相互作用的强弱，揭示催化剂结构以及表/界面特征与N2O分解性能之间的内在联系；进行金红石型氧化物稳定的Ir基催化剂结构设计和优化，实现具有特定纳米结构Ir基催化剂的可控合成，获得兼具耐高温稳定性和低温活性的推进级N2O分解催化剂。

中文关键词： 绿色推进剂；N2O分解；Ir催化剂；热稳定性；金红石

英文摘要： Nitrous oxide (N2O) has received much attention as a promising green propellant due to its low toxicity, self-pressurized feeding character and multiple modes of propulsion application. Iridium-based catalyst is highly active for N2O decomposition, but suffers from severe sintering due to the exothermic properties of this reaction. In this proposal, the rutile-type oxides, such as TiO2, SnO2, are employed to stabilize IrO2, the active sites for N2O decomposition. Both IrO2 and the supports have rutile structures, with lattice constants that are extremely similar to each other, thus making it possible to form strong interaction through chemical bonding. The influence of crystallite type, surface area, and pretreatment conditions on IrO2 particle size and morphology will be investigated in order to propose the stabilizing mechanism. Their nano-structure character will be detected by high resolution transmission electron microscopy combined with X-ray absorption spectroscopy. And the interface properties will be investigated by XPS, EPR, and microcalormetry as well to determine structure-reactivity relations. Rational optimization of catalyst microstructure based on the mechanistic insight will led to an iridium catalyst with both thermal stability and high catalytic activity for the catalytic decomposition of N2O propellant.

英文关键词： Green propellant;N2O decomposition;Ir catalyst;thermal stability;rutile