Reaction‐Induced Dynamic Evolution of In 2 O 3 During the Reverse Water‐Gas Shift (RWGS) Reaction

The In 2 O 3 based catalysts are promising for the reverse water‐gas shift (RWGS) reaction owing to their high selectivity. However, the dynamic structural and chemical evolution of In 2 O 3 under reactive atmosphere remains poorly understood. Herein, we elucidate the nanoscale dynamic evolution of In 2 O 3 during the RWGS reaction using in situ transmission electron microscopy (TEM), in situ X‐ray diffraction (XRD), quasi in situ X‐ray photoelectron spectroscopy (XPS), and in situ Raman spectroscopy. Our results reveal that In 2 O 3 undergoes substantial surface reconstruction at the early reaction stage in an H 2 /CO 2 atmosphere, forming mobile worm‐like In 2 O 3‐x nanorods even at temperatures as low as 150°C. These nanorods migrate and grow, increasing in width from 2.6 nm at 150°C to 8.5 nm at 400°C. Following this early‐stage transformation, the particle size of In 2 O 3 remains almost unchanged. The system subsequently enters a steady stage, governed by a dynamic balance between oxygen‐vacancy formation by H 2 reduction and vacancy ‘'re‐filling'’ by CO 2 . This work thus verifies the reaction‐induced dynamic evolution of In 2 O 3 for the RWGS reaction, where hydrogen acts as a key promoter and reaction temperature serves as a critical accelerator.