Unprecedented Catalytic Activity And Selectivity In Methanol Steam Reforming By Reactive Transformation Of Intermetallic In-Pt Compounds

Hydrogen storage in the form of small molecules and subsequent release are foreseen to play a fundamental role in future energy systems or carbon cycles. Methanol is an ideal hydrogen carrier due to the high H/C ratio, the lack of C-C bonds, and being liquid under ambient conditions. Methanol steam reforming is an advantageous reaction for the release of the chemically bound hydrogen. Pd- or Pt-based intermetallic compounds have shown to be CO2-selective and long-term stable catalytic materials. However, an intrinsic understanding of the underlying processes is still lacking. In this study, we show that the redox activity in the In-Pt system can be steered by gas-phase changes and leads to highly active catalytic materials at 300 degrees C [1500 mol (H-2)/(mol (Pt) x h)] with an excellent CO2 selectivity of 99.5%, thus clearly outperforming previous materials. Reactive transformations between In2Pt, In3Pt2, and In2O3 have been identified to cause the high selectivity. Redox activity of intermetallic compounds as part of the catalytic cycle was previously unknown and adds an understanding to the concept of different adsorption sites.