(678e) Cooperative Co (0)/Co (II) Sites Stabilized By a Perovskite Matrix Enable Selective C?O and C?C Bond Hydrogenolysis of Oxygenated Arenes

A strontium(Sr)‐substituted lanthanum cobaltite (La0.8Sr0.2CoO3) matrix stabilized Co(II)/Co(0) catalytic sites that featured 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 where Sr‐substitution facilitated oxygen vacancy formation and led to an order of magnitude 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 high selectivity towards C‐C hydrogenolysis at low PH2. Given that Co3O4 surfaces featured a narrower temperature window for obtaining the respective optimal Co(II) and Co(0) pairs compared to analogous perovskite surfaces, the perovskite matrix is implicated in stabilizing these pairs for selective C‐O and C‐C hydrogenolysis. This stabilization effect offers an additional handle to control reactivity in oxide catalysts.