Mechanisms and Reaction Intermediates for Photocatalytic Oxidation

法尔科纳教授将研究气相光催化氧化(PCO)的整体反应、表面过程和失活机理。重点将放在有机和氯化有机环境污染物的催化剂上，在接近室温的情况下，用近紫外光照明。探测反应物将是乙醇、三氯乙烯和甲苯。光催化剂将以二氧化钛、铂/二氧化钛和二氧化锰为基础，并将以0.5微米层的形式沉积在从外部照明的PYREX环形反应堆内壁上。稳定状态下吸附和共吸附的有机物种的浓度，PCO的表面活性位置的比例，以及上述所有物质在流动中随时间的衰减，都将被测定。还将研究负载型铂对二氧化钛活性、表面化学和失活的影响。一个主要目标是确定各种吸附物种对部分或全部氧化的选择性，以及控制这种选择性所需的条件。可使用的技术包括：稳态和瞬时等温反应，稳态和瞬时13C同位素示踪，程序升温脱附，氧化和氢化，以及FTIR。研究成果对废气中VOC的去除以及有机中间体的光化学合成具有重要意义。

Prof. Falconer will study the overall reaction, surface processes, and deactivation mechanisms of gas-phase photocatalytic oxidation (PCO). The focus will be on organic and chlorinated organic environmental contaminants over catalysts illuminated with near-UV light, at near room temperature. Probe reactants will be ethanol, trichloroethylene, and toluene. Photocatalysts will be based on TiO2, Pt/TiO2, and MnO, and will be deposited as 0.5 micron layers on the inside of a Pyrex annular reactor wall illuminated from the outside. The concentration of adsorbed and co-adsorbed organic species at steady state, the fraction of surface sites active for PCO, and the decay of all of the above over time on stream, are to be determined. The influence of supported Pt on the activity, surface chemistry, and deactivation of TiO2, will also be studied. A major goal is to determine the selectivity of the various adsorbed species towards partial or total oxidation, and the conditions needed to control such selectivity. Techniques to be used include: steady state and transient isothermal reaction, steady state and transient 13C isotope tracing, temperature-programmed desorption, oxidation and hydrogenation, and FTIR. The research outcome is of high significance for the elimination of VOC from waste air streams, as well as for the photochemical synthesis of organic intermediates.