Support effects and catalytic trends for water gas shift activity of transition metals

Surface Reaction Kinetics of Steam- and CO2-Reforming as Well as Oxidation of Methane over Nickel-Based Catalysts

“…Lin et al [82] showed that the formate path is energetically unfavorable in comparison to the redox and carboxyl mechanisms. The carboxyl mechanism is supported by Boisen et al [83], who assumed that the carboxyl species plays an important role especially on supports containing CeO2, regardless of the metal type, that the extraction of the first hydrogen from water is a slow step and that the subsequent reaction of CO and OH results in a carboxyl (COOH) intermediate which decomposes into CO2 and H2. Grabow et al [84] presented a micro-kinetic model as well as experimental data for the low-temperature water-gas shift (WGS) reaction catalyzed by Pt at temperatures ranging from 523 K to 573 K for various gas compositions at a pressure of 1 atm.…”

Natural gas to synthesis gas – Catalysts and catalytic processes

“…In this case the reactivity of the catalyst will depend on the length of the periphery of the metal particles. More recently, Boisen et al (2010) prepared a series of catalysts with 12 transition metals on Ce 0.75 Zr 0.25 O 2 and MgAl 2 O 4 supports. In general the activities were highest when the Ce 0.75 Zr 0.25 O 2 support was used, but for Cu and Au the highest activities were obtained using MgAl 2 O 4 support.…”

Surface Reaction Kinetics of the Oxidation and Reforming of CH4 over Rh/Al2 O3 Catalysts

“…Several studies already focused on the kinetics of CPOX of natural gas over Rh . Furthermore, the impact of the support and interactions on the molecular level were studied . The reaction schemes discussed for CPOx and reforming of CH 4 revealed that there is not a distinct boundary between these two catalytic paths, partial oxidation, and SR .…”

“…Since chemical conversion of methane in the presence of oxygen occurs within milliseconds and millimeters of a laboratory‐scale fixed‐bed reactor, capillary techniques have to be developed to resolve the concentration profiles . In addition, the modeling of these reactors is quite complex due to strong interactions of chemical kinetics and heat and mass transport in different phases and spatial directions .…”