Hybrid MOF Template-Directed Construction of Hollow-Structured In 2 O 3 @ZrO 2 Heterostructure for Enhancing Hydrogenation of CO 2 to Methanol.

Direct hydrogenation of CO 2  to methanol using green hydrogen has emerged as a promising method for carbon neutrality, but qualifying catalysts represent a grand challenge. In 2 O 3 /ZrO 2  catalyst has been extensively applied in methanol synthesis due to its superior activity; however, the electronic effect by strong oxides-support interactions between In 2 O 3  and ZrO 2  at the In 2 O 3 /ZrO 2  interface is poorly understood. In this work, abundant In 2 O 3 /ZrO 2  heterointerfaces are engineered in a hollow-structured In 2 O 3 @ZrO 2  heterostructure through a facile pyrolysis of a hybrid metal-organic framework precursor MIL-68@UiO-66. Owing to well-defined In 2 O 3 /ZrO 2  heterointerfaces, the resultant In 2 O 3 @ZrO 2  exhibits superior activity and stability toward CO 2  hydrogenation to methanol, which can afford a high methanol selectivity of 84.6% at a conversion of 10.4% at 290 °C, and 3.0 MPa with a methanol space-time yield of up to 0.29 g MeOH  g cat -1  h -1 . Extensive characterization demonstrates that there is a strong correlation between the strong electronic In 2 O 3 -ZrO 2  interaction and catalytic selectivity. At In 2 O 3 /ZrO 2  heterointerfaces, the electron tends to transfer from ZrO 2  to In 2 O 3  surface, which facilitates H 2  dissociation and the hydrogenation of formate (HCOO*) and methoxy (CH 3 O*) species to methanol. This study provides an insight into the In 2 O 3 -based catalysts and offers appealing opportunities for developing heterostructured CO 2  hydrogenation catalysts with excellent activity.