Homogeneously Distributed Cu-ZnO(-Al2O3) Nanoparticles Encapsulated with SiO2 Shells for Superior CO2 Hydrogenation Activity to Methanol

• Published in: ACS sustainable chemistry & engineering Vol. 12; no. 10; pp. 4245 - 4254
• Main Authors: Jeong, So Yun, Kim, Ji Hyun, Park, Min Jung, Wang, Xu, Bae, Jong Wook
• Format: Journal Article
• Language: English
• Published: American Chemical Society 11-03-2024
• Subjects: strong metal−support interaction (SMSI); CO2 hydrogenation to methanol; thermally stable SiO2 layers; core−shell-structured Cu-ZnO-(Al2O3)@SiO2; uniformly distributed nanoparticles
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.3c08330

Homogeneously distributed Cu-ZnO­(-Al2O3) nanoparticles encapsulated with SiO2 shells (denoted as Cu@Si, CZ@Si, and CZA@Si) are investigated to increase their thermal resistance for stable CO2 hydrogenation activity caused by the newly formed strong metal–support interaction (SMSI) of spatially confined CZA nanoparticles. The core–shell-structured CZA nanoparticles coated with protective silica shell layers revealed a higher CO2 hydrogenation activity to methanol with an excellent catalytic stability. The uniformly distributed core–shell-structured CZA nanoparticles ∼3 nm in size were found to be thermally stable even after CO2 hydrogenation reaction without any structural collapses and insignificant aggregations of the CZA nanoparticles. The spatially confined Cu-based nanoparticles with the help of the SiO2 protective shell layers having larger strong basic sites (oxygen vacant sites) showed a higher CO2 conversion of 11.0–15.8% and selectivity to methanol of 46.3–65.4% for a 200 h reaction, which were mainly attributed to their excellent antiaggregation characteristics through SMSI contributions between CZA core nanoparticles and thermally stable protective SiO2 shell layers.