Nanostructure of nickel-promoted indium oxide catalysts drives selectivity in CO<sub>2</sub> hydrogenation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33785755.
- Also identified by DOI 10.1038/s41467-021-22224-x and PMC identifier 8010022.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Metal promotion in heterogeneous catalysis requires nanoscale-precision architectures to attain maximized and durable benefits. Herein, we unravel the complex interplay between nanostructure and product selectivity of nickel-promoted In<sub>2</sub>O<sub>3</sub> in CO<sub>2</sub> hydrogenation to methanol through in-depth characterization, theoretical simulations, and kinetic analyses. Up to 10 wt.% nickel, InNi<sub>3</sub> patches are formed on the oxide surface, which cannot activate CO<sub>2</sub> but boost methanol production supplying neutral hydrogen species. Since protons and hydrides generated on In<sub>2</sub>O<sub>3</sub> drive methanol synthesis rather than the reverse water-gas shift but radicals foster both reactions, nickel-lean catalysts featuring nanometric alloy layers provide a favorable balance between charged and neutral hydrogen species. For nickel contents >10 wt.%, extended InNi<sub>3</sub> structures favor CO production and metallic nickel additionally present produces some methane. This study marks a step ahead towards green methanol synthesis and uncovers chemistry aspects of nickel that shall spark inspiration for other catalytic applications.