Selective conversion of CO2 to isobutane-enriched C4 alkanes over InZrOx-Beta composite catalyst

Direct conversion of CO2 to a specific hydrocarbon with high selectivity is attractive but challenging. Here the authors report a highly active InZrOx-Beta tandem catalyst for CO2 hydrogenation to butane and develop a surface silica protection strategy to inhibit the migration of indium species, greatly improving catalytic stability. Direct conversion of CO2 to a single specific hydrocarbon with high selectivity is extremely attractive but very challenging. Herein, by employing an InZrOx-Beta composite catalyst in the CO2 hydrogenation, a high selectivity of 53.4% to butane is achieved in hydrocarbons (CO free) under 315 degrees C and 3.0 MPa, at a CO2 conversion of 20.4%. Various characterizations and DFT calculation reveal that the generation of methanol-related intermediates by CO2 hydrogenation is closely related to the surface oxygen vacancies of InZrOx, which can be tuned through modulating the preparation methods. In contrast, the three-dimensional 12-ring channels of H-Beta conduces to forming higher methylbenzenes and methylnaphthalenes containing isopropyl side-chain, which favors the transformation of methanol-related intermediates to butane through alkyl side-chain elimination and subsequent methylation and hydrogenation. Moreover, the catalytic stability of InZrOx-Beta in the CO2 hydrogenation is considerably improved by a surface silica protection strategy which can effectively inhibit the indium migration.

Automated summary

The authors report a highly active InZrOx-Beta tandem catalyst for the direct conversion of CO2 to butane, and develop a surface silica protection strategy to improve catalytic stability by inhibiting the migration of indium species.