Single Crystal Adsorption Microcalorimetry

关于吸附过程的准确热力学信息对于建立对表面反应的机理理解至关重要。在大多数情况下，对于活性分子在特征良好的固体表面上的吸附，这些信息是不可用的。该研究项目得到了分析和表面化学项目的支持，旨在为一些具有重要催化作用的体系获得这类信息。这一信息将通过在超高真空条件下对表征良好的薄金属和金属氧化物单晶样品进行仔细的微热测量来获得。这项工作将着重于热解吸光谱等传统方法无法研究的系统。关于吸附键强度的详细信息，以及表面结构和组成对这些热力学性质的影响将得到。为了开发和探索这些技术上重要过程的反应机制，需要对吸附分子和催化表面之间的键合强度有一个基本的了解。该研究项目旨在开发和应用一种技术，用于直接测量在表征良好的催化表面上的吸附强度。所获得的热力学信息对于评估可能的表面反应机制和对催化重要过程有一个基本的了解是非常有用的。＊＊＊

9319234 Campbell Accurate thermodynamic information about adsorption processes is essential to developing a mechanistic understanding of surface reactions. This information is not available, for the most part, for adsorption of reactive molecular species on well characterized solid surfaces. This research project, supported in the Analytical and Suface Chemistry Program, is designed to obtain this sort of information for a number of catalytically important systems. This information will be obtained by careful microcalorimetry measurements on well characterized thin metal and metal oxide single crystal specimens under ultra high vacuum conditions. The work will emphasize systems which can not be studied by more traditional methods such as thermal desorption spectroscopy. Detailed information about adsorption bond strengths, and the effect of surface structure and composition on these thermodynamic properties will be obtained. %%% A basic understanding of the strength of bonding between an adsorbed molecule and a catalytic surface is needed in order to develop and probe reaction mechanisms for these technologically important processes. This research project is designed to develop and apply a technique for the direct measurement of this adsorption strength on well characterized catalytic surfaces. The thermodynamic information obtained will be very useful for evaluating possible surface reaction mechanisms and developing a basic understanding of catalytically important processes. ***