75 research outputs found
Core–shell catalyst pellets for effective reaction heat management
Catalyst research is concerned with synthesizing increasingly active materials, leading to safety issues at reactor scale, unless the reaction heat release is controllable. Computational studies predict that core–shell pellets with catalytically active core and inert shell are beneficial for this purpose, compared to established concepts such as catalyst pellet dilution. At high temperatures, reactant diffusion through the shell becomes rate-determining, resulting in a well-controllable heat release rate, which prevents further temperature increase. Here, industrial catalyst pellets were coated in a fluidized-bed pilot plant, demonstrating large-scale production feasibility. The obtained pellets were characterized via Dynamic Image Analysis, Scanning Electron Microscopy and X-ray Computed Tomography. Conducted CO2 methanation experiments confirm the predicted trends, if the applied shell is fully closed. Furthermore, mathematical and experimental studies demonstrate, that the inert shell shifts selectivity. Based on this work, safer and yet economical reactor operation is anticipated also for other reaction systems
Gold catalysts and the use thereof in the water-gas shift reaction
The present invention relates to a substrate for a gold catalyst, of formula CeO2 - ΜΟχ/ΑΙ2O3, wherein the substrate comprises between 60 and 90% w/w of Al2O3 and a percentage of CeO2 between 10 and 40% w/w, optionally doped with MOx oxide, with M selected from Fe, Zn, Co and Ni, Zr or mixtures thereof. The present invention relates to the use of the catalyst for the water-gas shift reaction and, more particularly, the use thereof in fuel cells
- …