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. (C) 2011 Elsevier B.V. All rights reserved.