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Comparison of surface coverage values of tungsten-alumina catalysts determined by different methods

“…The calculated W cross-sections (22 -24.5) A2/ W were in good agreement with other reports [3]. Another method which has been used to estimate apparent surface coverage in different supported metal oxide systems is the electrophoretic migration method (EM) [4].…”

“…Recently ion scattering spectroscopy (ISS) and low temperature CO adsorption have been ,used successfully to determine absolute surface coverages (0iss and 0co ) in molybdenum-alumina [2] and tungsten-alumina [3] catalysts. For the W-alumina catalysts, the 0co values were very similar to those obtained with the ISS method, for a particular loading.…”

“…The ZPC and IEP are used according to the definition of Parks [5]. Since this method involves surface coverage measurements that are made in solution, it is interesting to compare the values obtained for 0Eu, with those obtained by the aforementioned ISS and low temperature CO adsorption [3], where the corresponding 0 are measured in situ after pretreatment under different conditions.…”

Surface coverage of WO3/ZrO2 catalysts measured by ion scattering spectroscopy and low temperature CO adsorption

“…Clearly, the coverage values obtained from ISS are in reasonable agreement with those estimated from the CO adsorption method. This suggests that the proposed methodology for coverage measurements, which has proven e †ective for alumina-supported Mo, Re and W catalysts, 11,17,18 …”

“…This approach has proven e †ective for alumina-supported molybdenum (Mo), rhenium (Re) and tungsten (W) catalysts. 11,17,18 The present work is a part of a systematic study aimed at evaluating the potential use of the proposed methodology when other supports are used. The study will be restricted to the system.…”