Dry reforming of methane in a stagnation-flow reactor using Rh supported on strontium-substituted hexaaluminate

A combination of experiment and modeling is used to investigate catalytic reforming of methane with carbon dioxide (dry reforming) in a stagnation-flow reactor. The catalyst surface is a porous washcoat of rhodium supported on strontium-substituted hexaaluminate. The stagnation-flow configuration enables microprobe sampling of the compositional boundary layer adjacent to the catalyst surface. This configuration also enables efficient modeling the heterogeneous chemistry, coupled with convective and diffusive transport within the gas-phase boundary layer. The measurements provide new data that assist the fundamental understanding of methane dry reforming. The modeling incorporates an elementary reaction mechanism that was developed initially to represent catalytic partial oxidation and steam reforming. Representing the new dry-reforming measurements required modification of reaction rates for CO2 and CH4 interactions on the catalyst surface.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (152 K)Download as PowerPoint slideResearch highlights▶ Stagnation-flow reactor provides new experimental data to assist in extending previously published reaction mechanisms to a greater range of conditions. ▶ Effective modeling of dry reforming methane is most sensitive to three elementary reaction rates identified here. ▶ Reaction pathways show that the adsorbed HCO species is an important reaction step in modeling dry reforming of methane. ▶ In the present reaction pathway surface carbon is oxidized primarily by surface atomic oxygen from HCO*.