Investigation of NO interaction on Rh/doped TiO

The interaction of NO with Rh supported on W+6 doped TiO2 has been investigated by coupling transient diffuse reflectance Fourier transform Infrared spectroscopy and mass spectrometry. The experiments were carried out in dynamic conditions (under reactant flow and at temperature reaction) at atmospheric pressure. By comparing the results obtained with undoped Rh/TiO2 and Rh/TiO2(W6+) catalysts, the analytical approach used permitted to emphasis the effect of carrier doping, with respect to the elementary steps and surface intermediates involved in NO interaction process. It was found that W6+-doping of TiO2 promotes significantly the formation of Rh-NO- species and enhances the thermal stability of Rh-NO+ on Rh/TiO2 (W6+) surfaces. This leads to a drastic increase in the selectivity of NO decomposition reaction towards N2 formation, whereas the N2O yield decreases significantly

Chemical reaction engineering and catalysis issues in future distributed power generation systems

Summarization: Three issues are most critical in fuel processors which are integrated with polymer electrolyte membrane (PEM) fuel cells for power generation: the steam reformer configuration, which must ensure very rapid heat transfer to the reformation zone, the development of highly active catalysts for the water−gas shift (WGS) reaction and the development of highly selective catalysts for the methanation reaction. The heat-integrated wall reactor (HIWAR), in either the tubular or the plate form, which offers very rapid heat exchange between a combustion and a reformation zone, is proposed. This configuration results in high efficiency and compact design. Platinum catalysts supported on a “reducible” metal oxide such as TiO2 exhibit high WGS activity, which can be further improved with the addition of alkali or alkaline earth promoters. Titania-supported ruthenium catalysts are capable of completely and selectively methanate CO in the presence of excess CO2, provided that catalyst characteristics are optimized and operating conditions are properly selected. Integration of the three developments can result in efficient power generation systems.Παρουσιάστηκε στο: Industrial and Engineering Chemistry Researc