Dynamic Restructuring of Rh/In ₂ O _{3– <i>x</i>} on ZrO ₂ Support for Promoted Selective Hydrogenation of CO ₂ to Methanol

The Rh/In 2 O 3 /ZrO 2 ternary catalyst exhibits higher activity for the selective CO 2 hydrogenation to methanol compared to the Rh/In 2 O 3 catalyst. The dynamic structural and chemical evolution of In 2 O 3 under reaction conditions plays a pivotal yet underexplored role in governing the catalytic behavior of Rh/In 2 O 3 /ZrO 2 . Through comparative investigations of Rh/In 2 O 3 /ZrO 2 and Rh/ZrO 2 catalysts, the critical role of In 2 O 3 is elucidated in modulating the structural and electronic configurations of the active sites. The analyses with in situ transmission electron microscopy (TEM), in situ Raman spectroscopy, and quasi in situ X-ray photoelectron spectroscopy (XPS) reveal the transformation of cubic In 2 O 3 into disordered In 2 O 3– x nanolayers on ZrO 2, creating abundant In 2 O 3– x /ZrO 2 interfaces enriched with oxygen vacancies. Simultaneously, the restructured Rh/In 2 O 3– x interface induces pronounced metal–support interactions, synergistically enhancing CO 2 chemisorption while maintaining the H 2 dissociation capability. This dual functionality preferentially stabilizes HCOO* intermediates, dramatically shifting product selectivity from methane (97.0%) over Rh/ZrO 2 to methanol (81.0%) with ignorable methane formation on Rh/In 2 O 3 /ZrO 2, at 300 °C and 5 MPa, as an example. This work shows the effect of the In 2 O 3 -mediated dynamic reconstruction on the selection of the reaction pathway for CO 2 hydrogenation. The new insights into the structure–activity relationship of the Rh/In 2 O 3 /ZrO 2 catalyst are provided.