FTIR study of CO adsorption on molybdena-alumina catalysts for surface characterization

Abstract

CO adsorption at low temperature has been used to probe Lewis acid sites created upon dehydroxylation of γ-Al 2 O 3 and reduction of Mo/Al 2 O 3 catalysts, using Fourier Transform Infrared spectroscopy (FTIR). Carbon-monoxide adsorption on γ-Al 2 O 3 and Mo/Al 2 O 3 catalysts dehydroxylated and reduced at different temperatures was studied at 78 K by IR spectroscopy. However, our results indicate that there is an approximately linear correlation between the increase either of dehydroxylation or the extent of reduction of the catalysts and the increasing absorbance of CO due to CO adsorption on Lewis acid sites created upon dehydroxylation of γ-Al 2 O 3 and reduction of Mo/Al 2 O 3 .

CO Desorption Ability from Pt Enhanced by Al2O3: An in Situ Real-Time Attenuated Total Reflection Infrared Investigation

“…We also investigated the CO adsorption on Al 2 O 3 film for comparison, but no peaks were observed (the spectrum is not shown here). In a previous study, Nasser et al have investigated the CO adsorption on Al 2 O 3 by using transmission FTIR, and they found that CO weakly adsorbed on Al 2 O 3. Since ATR-IR has a much weaker signal than that of transmission FTIR combined with the weak adsorption of CO on oxides, CO peaks on Al 2 O 3 were not observed by using ATR-IR in this study.…”

Effects of cobalt promoter and reduction temperature on the surface species and syngas adsorption of K–Co–Mo/C catalyst for mixed alcohols synthesis

“…The weak bands at 2080-2100 cm −1 can be assigned to the CO adsorption on the Mo center in lower oxidation state [23]. Besides, the bands at 2150 cm −1 and 2138 cm −1 may be assigned to CO adsorption on Mo-OH [24]. With cobalt addition, it was observed that the new bands at 2130 cm −1 , 2170 cm −1 and 2186 cm −1 appeared, which can be attributed to CO adsorbed on Co 1+ , Co 2+ and Co x+ respectively [25].…”