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Conversion of d -glucose to 5-hydroxymethylfurfural using Al 2 O 3 -promoted sulphated tin oxide as catalyst

“…The bands observed for the catalysts exhibited characteristic vibrational modes between 3000 and 3500 cm −1 and around 1600 cm −1 assigned to OH bonds. These bands correspond to hydroxyl groups bonded to adjacent Sn sites [20,[26][27][28]. Adsorption bands related to the addition of sulphur groups on the tin oxide catalyst were observed in the region of 980-1200 cm −1 , as has been reported elsewhere [29].…”

In Situ and Operando Spectroscopy for Assessing Mechanisms of Gas Sensing

“…Numerous experimental and theoretical works have evaluated this explanation of gas-sensing effects (see, for example, references [86,[90][91][92][93][94][95]), and it dominates in almost all spectroscopic studies (see, for example, references [35,[96][97][98][99][100]). Several problems, however, are often not considered or avoided by the nonrealistic experimental conditions.…”

In situ Raman spectroscopy study of NO2 adsorption onto nanocrystalline tin(IV) oxide

“…3,8 However, few studies are focused on the understanding of the adsorption and/or reaction phenomena that take place at the SnO 2 surface and can explain its electrical response to pollutant gases. 9,10 Among the various techniques that are able to provide information about the surface of materials, Raman spectroscopy is probably one of the most popular, mostly because it can be used in situ, in true working conditions. However, its intrinsic low cross section is a strong limitation when the signal originates from a limited number of sites, as in surface adsorption.…”