Regulating the Crystal Facet Differences of In2O3 via Different Precipitants to Affect Methanol Selectivity

Graphical Three indium trioxide (In 2 O 3 ) catalysts with varied morphologies and exposed crystal facets were synthesized. The catalyst with a predominantly exposed (211) facet achieved notable CO 2 conversion and CH 3 OH selectivity. This underscores the role of crystal facet engineering in improving catalyst performance for sustainable methanol production. Under the background of “carbon peak and carbon neutrality”, the hydrogenation of carbon dioxide (CO 2 ) to methanol (CH 3 OH) represents a crucial pathway for promoting green and sustainable development. In 2 O 3 has gained attention as a promising material for CH 3 OH production from CO 2 due to its controllable properties including morphologies, particle sizes and oxygen vacancies, along with its excellent selectivity in CO 2 hydrogenation reactions. Herein, by employing various precursors, three distinct indium trioxide (In 2 O 3 ) catalysts with varied morphologies and predominantly exposed crystal facets were synthesized. It is found that the In 2 O 3 catalyst prepared using ammonia monohydrate (NH 3 ⋅H 2 O) as a precipitator exhibits a primarily exposed (211) crystal facet. This catalyst demonstrates a CO 2 conversion rate of 4.7 %, a selectivity of 55 %towards CH 3 OH, and a space velocity of 8000 ml g cat. −1 h −1 , under reaction conditions of 280 °C and 3 MPa. The (211) crystal face of In 2 O 3 is conducive to the generation of oxygen vacancies which shows exceptional active capabilities for CO 2 , and thus showing outstanding advantages in the selectivity towards CH 3 OH. The results underscore the importance of crystal facet engineering in tailoring the properties of catalysts for efficient CO 2 hydrogenation to CH 3 OH.