Revealing the effect of metal-support interactions at the Ni/In 2 O 3 (111) interface on the selective CO 2 hydrogenation

In 2 O 3 -supported Ni catalysts exhibit remarkable catalytic activity and selectivity in CO 2 hydrogenation to methanol, but the underlying mechanisms and metal-oxide interactions during the reaction remain elusive. Herein, we investigate the Ni-In 2 O 3 interaction by physical vapor deposition of Ni onto well-defined In 2 O 3 (111) thin films. In-situ near ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) was employed to probe the CO 2 hydrogenation processes on these Ni/In 2 O 3 (111) model systems. Our results reveal that the small Ni clusters supported on the In 2 O 3 (111) surface at low Ni coverages exhibit cationic states. The chemical bonding and associated electron transfer at the Ni/In 2 O 3 (111) interface play crucial roles in the activation of H 2 and CO 2. Importantly, reaction intermediates (CO 3 *, OH, and HCOO*) are readily formed and desorbed under CO 2 hydrogenation conditions. Our study highlights the significance of metal-support interactions on the selectivity of CO 2 hydrogenation. These findings provide valuable insights into the rational design of advanced In 2 O 3 -based catalysts for CO 2 hydrogenation.