Development of a RhZrO2 catalyst for low temperature autothermal reforming of methane in membrane reactors

摘要

A Rh-based catalyst for low temperature hydrogen generation in membrane microreactor applications has been developed and characterized. A RhZrO2 catalyst with 1.4wt% Rh was prepared by incipient wetness impregnation and was tested for both methane reforming and autothermal reforming at temperatures interesting for membrane reactor applications (i.e. temperatures below 700 °C and steam-to-carbon ratio of 2). The kinetic parameters to describe the reaction rate of both methane steam reforming (SMR) and auto-thermal reforming (ATR) over the RhZrO2 catalyst have been determined using a 1D heterogeneous packed bed reactor model to properly account for mass and heat transfer resistances. The experimental results demonstrate that the RhZrO2 catalyst is extremely active for ATR and resistant to coke formation at much lower temperatures and steam-to-carbon ratios compared with conventional Ni-based catalysts. This makes the new catalyst especially suitable for integration in a Pd-based membrane microreactor with a maximum allowable operation temperature of about 650 °C dictated by the membrane stability.