Publications by authors named "Vera P Santos"

The structure and elementary composition of various commercial Fe-based MOFs used as precursors for Fischer-Tropsch synthesis (FTS) catalysts have a large influence on the high-temperature FTS activity and selectivity of the resulting Fe on carbon composites. The selected Fe-MOF topologies (MIL-68, MIL-88A, MIL-100, MIL-101, MIL-127, and Fe-BTC) differ from each other in terms of porosity, surface area, Fe and heteroatom content, crystal density and thermal stability. They are re-engineered towards FTS catalysts by means of simple pyrolysis at 500 °C under a N atmosphere and afterwards characterized in terms of porosity, crystallite phase, bulk and surface Fe content, Fe nanoparticle size and oxidation state.

View Article and Find Full Text PDF

Cryptomelane-type manganese oxides were synthesized by redox reaction under acid and reflux conditions. Different metals (cesium, lithium and titanium) were incorporated into the tunnel structure by the ion-exchange technique. Gold was loaded onto these materials (1wt%) by a double impregnation method.

View Article and Find Full Text PDF

Depletion of crude oil resources and environmental concerns have driven a worldwide research on alternative processes for the production of commodity chemicals. Fischer-Tropsch synthesis is a process for flexible production of key chemicals from synthesis gas originating from non-petroleum-based sources. Although the use of iron-based catalysts would be preferred over the widely used cobalt, manufacturing methods that prevent their fast deactivation because of sintering, carbon deposition and phase changes have proven challenging.

View Article and Find Full Text PDF