Preferential cleavage of C[sbnd]C bonds over C[sbnd]N bonds at interfacial CuO[sbnd]Cu2O sites

Abstract

Creation of substrate-accessible interfacial defect sites will bring about new catalytic discoveries because substrate binding and activation on these sites are pivotal for controlling reaction intermediate and product selectivity. The partial oxidation of pristine Cu2O can lead to an excellent selective oxidation catalyst (CuO/Cu2O). The CuO/Cu2O, containing embedded CuO nanodomains on the surface and possessing abundant coordinatively unsaturated copper sites at the CuOCu2O interface, shows very high activity toward CC bond cleavage and excellent selectivity toward formamides in trialkylamines oxidation. This result is exceptional because the previous works mainly offer dealkylated amines via CN bond cleavage. The unusual catalysis by CuO/Cu2O is attributed to the co-activation of oxygen and amines in close proximity at the CuOCu2O interface. The present study contributes a new concept of delicate controlling substrate-accessible interfacial active sites on pristine oxide surfaces, and also offers a novel formamide synthesis method by trialkylamine oxidation.