Intensified O2 activation and lattice O supply at inverse oxide-metal interface for catalytic oxidation reactions: A case study in alcohol oxidation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-10, Vol.498, p.155443, Article 155443
• Main Authors: Liu, Kun, Sun, Yongbin, Si, Jiaqi, Fu, Cong, Bi, Yushui, Zhao, Xiaomin, Zhao, Guofeng
• Format: Article
• Language: English
• Subjects: Bond weakening; CoOx-Au; Inverse catalyst; O2 activation; Redox cycle
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155443

[Display omitted] •Highly active and stable inverse CoO-Au ensemble is fabricated for catalytic oxidation reactions.•The redox cycle of Co3O4 ↔ CoO is promoted by Au.•O2 activation and lattice O supply is intensified at CoOx-Au interface.•Co-O bond is weakened at CoOx-Au interface.•CoO-Au interface could be extended to other inverse oxide-metal interfaces. Inverse oxide/metal catalysts are recently employed and of great importance in catalytic oxidation reactions, due to the high activity and sintering-resistance. However, the investigations for identification of active-site structure, adsorption-activation of O2, and insight into interface-enhanced mechanism are relatively scare. Herein, the inverse “CoOx-Au” ensemble (∼10 nm CoOx nanoparticles onto ∼30 nm Au particles) for gas-phase alcohol oxidation was exampled to investigate above issues, under the premise of delivering 92 % benzyl alcohol conversion with 98 % benzaldehyde selectivity at 240 °C and atmospheric pressure. It is revealed that O2 is activated at CoOx-Au interface. The “CoO-Au ↔ Co3O4-Au” redox cycle at CoOx-Au interface proceeds over the “CoO↔Co3O4” cycle on CoOx surface, due to the weakened interfacial Co-O bond. And the enhanced redox cycle intensifies O2 activation and lattice O supply. The O2 activation at inverse oxide-metal interface provides promising clue for rational design of inverse catalysts for catalytic oxidation reactions.