Cooperative Co0/CoII Sites Stabilized by a Perovskite Matrix Enable Selective C−O and C−C bond Hydrogenolysis of Oxygenated Arenes. Issue 10 (18th April 2019)

• Record Type: Journal Article
• Authors: Shetty, Manish; Zanchet, Daniela; Green, William H.; Román‐Leshkov, Yuriy
• Is Part Of: ChemSusChem. Volume 12:Issue 10(2019)
• Page Start: 2171
• Page End: 2175
• Publication Date: 2019-04-18
• Subjects: biomass conversion -- heterogeneous catalysis -- metal–metal oxide interface -- perovskite -- reaction mechanisms; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201900664
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Strontium‐substituted lanthanum cobaltite (La0.8 Sr0.2 CoO3 ) matrix‐stabilized Co 0 /Co II catalytic sites were prepared, which present tunable C−O and C−C hydrogenolysis activity for the vapor‐phase upgrading of oxygenated arenes. Co II sites associated with oxygen vacancies were favored at low temperatures and performed selective C−O hydrogenolysis, in which Sr‐substitution facilitated oxygen vacancy formation, leading to approximately 10 times higher reactivity compared to undoped LaCoO3 . Co 0 sites were favored at high temperatures and performed extensive C−C bond hydrogenolysis, generating a wide range of alkanes. The lower reaction order with P H 2 (1.1±0.1) for C−C hydrogenolysis than for C−O hydrogenolysis (2.0±0.1) led to a high selectivity towards C−C hydrogenolysis at low P H 2 . The Co3 O4 surfaces featured a narrower temperature window for obtaining the respective optimal Co II and Co 0 pairs compared to analogous perovskite surfaces; whereas, the perovskite matrix stabilizes these pairs for selective C−O and C−C hydrogenolysis. This stabilization effect offers an additional handle to control reactivity in oxide catalysts. Abstract : Stronger, stable, and selective with Sr : Strontium‐substituted lanthanum cobaltite (La0.8 Sr0.2 CoO3 ) provides an ideal perovskite matrix that stabilizes Co 0 /Co II pairs. The proximate and simultaneous presence of oxygen deficient sites along with metallic Co enable tunable C−O and C−C bond hydrogenolysis of lignin‐derived oxygenated arenes.