Conventional methods for preparing noble metal catalysts supported on cordierite monoliths often necessitate high-temperature hydrogen prereduction to attain catalytic activity. However, these catalysts exhibit minimal activity in hydrogen combustion at ambient temperatures. In this study, we introduce a low-temperature preparation technique for Pt-Co and Pd-Co monolithic catalysts based on cordierite, leveraging the concept of gibbsite anchoring combined with freeze-drying. Initially, a gibbsite transition layer is applied to the cordierite surface. The bridging hydroxyl groups situated at the interlayer channel entrances of the gibbsite serve as robust anchoring sites for both noble metal precursors and Co ions. Subsequently, freeze-drying ensures molecular-level dispersion of these precursors. Following low-temperature calcination in air within the range of 350-400 ℃, highly active noble metal species and noble metal-CoO_x interfacial structures are directly obtained without any prior hydrogen prereduction. Our experimental findings reveal that the Pt-Co/cordierite catalyst achieves an H₂ conversion rate of 25-40% at room temperature (22-25 ℃) using a 2% H₂/air mixture, while the Pd-Co catalyst yields a conversion rate of 20-35%. For comparison, a sample prepared through traditional oven drying under identical conditions shows less than 5% conversion. This innovative method boasts straightforward processing, eliminates the need for prereduction, and offers cost control, presenting a promising approach for fabricating monolithic catalysts tailored for low-temperature catalytic hydrogen combustion and passive hydrogen removal.

PAR; Freeze-drying; Gibbsite; Pd-Co catalyst; Room-temperature catalysis.