Methanethiol adsorption

At the adsorption of benzenethiol on Ni(100), benzene and hydrogen are the only gas-phase products.370 Methanethiol adsorption has also been studied... 

The smallest molecule in the class is methanethiol, which has been studied at several surfaces as an indicator for the behaviour of larger thiols. On all metals, except gold, adsorption results in the dissociation of the S H bond. Yates and co-workers suggested47 that the S-H bond of methanethiol is also stable on silver, dissociation being catalysed by adsorbed sulfur present at defect sites. However, this contradicts Jaffey and Madix s results,56 which showed S-H bond cleavage below 350 K in their study of ethanethiol on Ag(lll). 

Figure 7 shows the activity and selectivity towards sulfur compounds of H-NbMCM-41 with various Si/Nb ratio H-NbMCM-41 seems to be a good catalyst as far as the formation of methanethiol is concerned. All hydrogen forms of niobium-containing MCM-41 materials are very stable in the production of sulfur compounds. The reason for that is the low acidity of the material, the absence of dissociative adsorption of H2S, and very easy formation of methoxy species on the surface as demonstrated earlier on the basis of IR measurements [3,10] If the mesoporous matrix possesses A1 instead of Nb, the MeOH conversion is higher, but the selectivity to methanothiol is lower. 

H-NbMCM-41 sieves appeared to be useful catalysts in the hydrosulfiirization of methanol towards methanethiol thanks to the presence of LAS and BAS pairs, low strength of acidic sites (side reactions are minimized), and the absence of dissociative adsorption of H2S... 

Activated carbons are used as an adsorbent to remove methanethiol (methylmer-captan), CH3SH, from air [22]. CH3SH is used at low mass fractions in natural gas as an odorant for leak detection. Bashkova eta . [22] measured CH3SH capacities between 0.03 and 0.35 g per gram of adsorbent. Functional groups, such as iron, catalyze the oxidation of adsorbed methanethiol to disulfides. In wet gases, there is competitive adsorption between water and disulfides. 

SSIMS has also been used in the study of the adsorption of propene on ruthenium [194], the decomposition of ammonia on silicon [195], and the decomposition of methanethiol on nickel[ 196]. 

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