Cooperative Co-0/Co-II Sites Stabilized by a Perovskite Matrix Enable Selective C-O and C-C bond Hydrogenolysis of Oxygenated Arenes

Author(s)

Shetty, Manish ^[1] ; Zanchet, Daniela ^{[2, 1]} ; Green, William H. ^[1] ; Roman-Leshkov, Yuriy ^[1]

Affiliation

^[1] MIT, Dept Chem Engn, Cambridge, MA 02139 - USA

^[2] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: CHEMSUSCHEM; v. 12, n. 10, p. 2171-2175, MAY 21 2019.
• Web of Science Citations: 2

Abstract

Strontium-substituted lanthanum cobaltite (La0.8Sr0.2CoO3) 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 10times 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 PH2 (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 PH2 . The Co3O4 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. (AU)

• FAPESP's process: 15/23900-2 - Earth-abundant materials as next-generation catalytic platforms for the conversion of lignocellulosic biomass
• Grantee: Daniela Zanchet
• Support Opportunities: Scholarships abroad - Research