Methanol: A chemical probe and hydrogen source by catalytic partial oxidation

Studies of two novel applications of methanol partial oxidation were conducted. One is the investigation of catalytic performances of V/SiO 2 and V/MgO catalysts prepared from two support morphologies (conventionally prepared and aerogel prepared); the other is an exploration of the mechanism of hydrogen generation on supported Cu and Pt catalysts.;Aerogel prepared supports hold higher surface areas than conventionally prepared supports. This provides sufficient sites for anchoring vanadium, yielding small vanadia domains. On the contrary, conventionally prepared supports possess less space for locating surface vanadium oxides, and bulk vanadia phases were found.;Both aerogel prepared V/SiO2 and V/MgO were more active than conventionally prepared catalysts for methanol partial oxidation. The differences in catalytic results were attributed to the configurations of active phases. Moreover, activity of small vanadia domain was higher than bulk phases, which was proved by the relation between vanadium surface density and turnover frequency.;Hydrogen generation by methanol partial oxidation on supported Cu and Pt showed a significant difference in the product distribution pattern. This deviation was investigated by determining the kinetics of each individual reaction which may play a role in hydrogen production. The selectivities of products are highly dependent on the rate of catalytic partial oxidation and methanol decomposition, whereas steam reforming and water-gas shift are not important. In addition, deactivation of Cu catalysts was studied, which may be attributed to the deposition of carbon on the catalyst's surface instead of active phase sintering.;The water-gas shift reaction is a favorable secondary reaction in the partial oxidation of methanol because it converts CO and H2O to CO2 and H2. Thus, a promising water-gas shift promoting catalyst, ceria-containing Pt catalysts, was examined. Ceria-promoted Pt/ZrO 2 catalysts were found to be active in water-gas shift reaction at low flow rate and were capable of enhancing complete combustion or dampening methanol decomposition.;Catalytic pathways of water-gas shift reaction were identified via a graph-theoretic method based on P-graphs. 116 stoichiometrically feasible pathways, instead of 70 found in earlier study, were discovered. Moreover, 5 instead of 3 pathways were determined to be energetically favorable.