Methanol oxidation activity uptake

Figure 2. Methanol oxidation activity at 150°C as a function of ammonia uptake at 150°C on V20g/Ti02(A)...

Monolayer coverage of vanadium oxide on tin oxide support was determined by a simple method of low temperature oxygen chemisorption and was supported by solid-state NMR and ESR techniques. These results clearly indicate the completion of a monolayer formation at about 3.2 wt.% V2O5 on tin oxide support (30 m g" surface area). The oxygen uptake capacity of the catalysts directly correlates with their catalytic activity for the partial oxidation of methanol confirming that the sites responsible for oxygen chemisorption and oxidation activity are one and the same. The monolayer catalysts are the best partial oxidation catalysts. 

Catalytic activities of the silica-supported vanadium oxides in either 3% methanol or in 5% O2 and 3% ethanol. Oxygen uptake was measured at 625 K. O2 and 3%... 

In this communication, the results of a systematic study of ammonia chemisorption on V2O -Ti02 (anatase) catalysts of different vanadia loading is reported." Low temperature oxygen chemisorption is also utilized to determine the monolayer loading of 20 on Ti02 (anatase). Partial oxidation of methanol to formaldehyde is studied as a model reaction on these catalysts and the activities of the catalysts are correlated with NH and O2 uptakes. 

The conversion of methanol is plotted as a function of NIL uptake in Fig. 2. From this figure it appears that ammonia uptake at 150°C reasonably correlates with methanol conversion at 150°C indicating that ammonia uptake is a measure of active sites upon which the reaction takes place. This finding supports the observation of Ai (47) that the oxidation of hydrocarbon is derived... 

Hydroformylation of 1-hexene was studied at 80 °C under 30 bar of CO/H2 (1 1) with the in-situ generated catalyst 7. The reaction was monitored via the CO/H2-uptake which was measured with mass flow meters. The polymer-bound catalysts possessed moderate activities in methanol (200-400 TO/h), and the activity was approx. 4-times higher when non polymer-bound TPPMS was used as the ligand. The activity of the catalyst 7 decreased in recycling experiments (entries 2a-2b in Table 2), which can presumably be attributed to a partial oxidation of the phosphine ligands. Moreover, the activity of the complex was not significantly affected by the change of P Rh... 

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