Properties of Bulk In-Pt Intermetallic Compounds in Methanol Steam Reforming

Heterogeneous catalysts are often complex materials containing different compounds. While this can lead to highly beneficial interfaces, it is difficult to identify the role of single components. In methanol steam reforming (MSR), the interplay between intermetallic compounds, supporting oxides and redox reactions leads to highly active and CO₂ -selective materials. Herein, the intrinsic catalytic properties of unsupported In₃ Pt₂ , In₂ Pt, and In₇ Pt₃ as model systems for Pt/In₂ O₃ -based catalytic materials in MSR are addressed. In₂ Pt was identified as the essential compound responsible for the reported excellent CO₂ -selectivity of 99.5 % at 300 °C in supported systems, showing a CO₂ -selectivity above 99 % even at 400 °C. Additionally, the partial oxidation of In₇ Pt₃ revealed that too much In₂ O₃ is detrimental for the catalytic properties. The study highlights the crucial role of intermetallic In-Pt compounds in Pt/In₂ O₃ materials with excellent CO₂ -selectivity.