Phase 3: a combined theoretical and experimental study of catalytic performance of cubic molybdenum and tungsten carbides for co2 and co reduction

Descripción

Presently, the majority of the actual energy demand is met with fossil fuels. however, because of the constantly rising price of energy sources and increasing demand for them, energy production is becoming one of the biggest concerns of modern civilization. also, heavy emission of co2 into the atmosphere causes negative effects, such as climate changes. possible approach to solving this problem is co2 catalytic reduction to higher energy compounds that could be afterwards combusted, producing energy, or used in fuel cells, releasing carbon dioxide. in 1973, levi and boudart reported that tungsten carbide possesses catalytic activity for hydrogenation reactions similar to activity of platinum. tungsten carbides wc and w2c also exhibit catalytic activity towards formation of ch4 and certain light hydrocarbons with carbon chain length not exceeding 4. while co2 reduction in the gas phase on hexagonal tmc is quite well studied, there is little to none information whether cubic phases of the corresponding materials have comparable properties. also there are no data available on co2 electrocatalytic reduction on cubic tmc, thus a big group of potentially active compounds for co2 electrochemical reduction is being overlooked. cubic moc and wc will be tested for co2 and co reduction in gas phase and in electrochemical medium and the results will be compared to available data on corresponding hexagonal carbides.
a theoretical study will be conducted on stepped (331) and (553) fcc moc and wc surfaces in order to account for specific adsorption sites present on tmc nanoparticles such as edge sites absent on low-index surfaces. effect of (111) terrace width on co and co2 stability on stepped surfaces will be estimated. it is expected that this approach could offer a better understanding of how defects of crystalline structure influence the adsorbatesurface interactions and allow a better theoretical description of tmc systems.

Objetivo

General the main objective of the present proposal is to determine catalytic properties of cubic moc and wc towards carbon dioxide and carbon monoxide reduction reaction. specific to study theoretically cubic wc and moc stepped surfaces with (111) terrace and (110) steps. to identify sites that are not available on low index surfaces and compare co and co2 stability on these sites with the stability of the same adsorbates on low-index surfaces. to synthetize cubic phases of moc and wc. to characterize cubic phases of moc and wc. to evaluate the catalytic activity for the co2 and co reduction on cubic moc and wc in gas phase and in electrochemical conditions. to compare theoretical calculations with experimental results about the catalytic activity
data and try to correlate them with the characterization information.
EstadoActivo
Fecha de inicio / finalización efectiva1/05/1930/05/20