Identification of Highly Active Co-O-Zn Sites in Silanol Nests for n-Butane Cascade Dehydrogenation to 1,3-Butadiene

n-Butane dehydrogenation (BDH) provides an on-purpose route to produce 1,3-BD. However, design of highly active and selective catalysts targeting BDH to 1,3-BD remains challenging because the activation barrier for the dehydrogenation of 1-butene (a primary product of BDH) is high and 1-butene readily isomerizes. Here, we report a bimetallic Co-O-Zn active site with the structure of ≡SiO-Co-O-Zn-OSi≡ prepared by reacting Co ions with ≡SiOZn-OH nests on dealuminated zeolite BEA (DeAlBEA), showing 3- and 34-fold activity advantages over monometallic Co and Zn counterparts, respectively. Co-O-Zn sites exhibit a high BDH rate of 354 mol·mol_Co^-1·h^-1 and a 1,3-BD productivity of 110 mol·mol_Co^-1·h^-1 (and selectivity to 1,3-BD of 31%) at 823 K. The forward rate coefficient for BDH is superior to state-of-the-art non-noble-metal catalysts and comparable to Pt-based catalysts. A kinetics investigation suggests that the Co-O-Zn interactions promote n-butane adsorption and activation of the C-H bond during both BDH and 1-butene dehydrogenation. Our work demonstrates a promising pathway for producing 1,3-BD via BDH using a catalyst that is free of expensive noble metals.