Pt-Promoted In2O3 Reduction and Reconstruction at the Pt/In2O3 Interface in CO2 Hydrogenation Atmosphere

As an essential path toward the elucidation of the reaction mechanism, the capture of the catalytically active phase and its evolution has been the primary goal of mechanistic studies. Here, the physicochemical properties on In2O3 (111) and Pt/In2O3 (111) thin film model catalysts were tracked in CO2 hydrogenation atmosphere under various pressures and temperatures by ambient pressure X-ray photoelectron spectroscopy (APXPS). The redox behaviours of surface Pt and In2O3, the formation and interconversion of reaction intermediates, and the structural dynamics at the topmost surface, as a consequence of the outward diffusion of InOx species, nucleation of surface Pt nanostructures and the formation of PtInOx species, were captured and analyzed. The reconstruction at the Pt/In2O3 (111) interface was also observed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and scanning electron microscopy (SEM) analysis. In-situ spectroscopic and structural analysis on a well-defined metal/metal-oxide interface offers a powerful means to probe the mechanistic details of the heterogeneous processes.