Construction Co-ZnO acid-base pair catalysts for alcohol and nitrobenzene hydrogen transfer cascade reaction

The strength and micro-distance of acidic and basic sites on acid-base pair catalysts (ABPC) are crucial in determining their synergistic effect and catalytic capacity, yet challenging in the synthesis of effective ABPC due to the tunable difficulties. Here, a Co-ZnO ABPC, containing adjacent Co single atoms-ZnO nanocluster acid-base pairs, was prepared by pyrolyzing ZnCo ZIF-precursor under vacuum. Benefiting from the unique acid-base pair features, Co-ZnO ABPC exhibited outstanding performance for the catalytic hydrogen transfer (CHT) cascade reaction, achieving high nitrobenzene conversion (95%) and imine selectivity (98%) at 160 ℃ for 3 h, exceeded almost all the documented catalysts. Both the experimental and calculation results verified the stronger acidity of Co SAs and the synergistic effect of acid-base sites lowered the free energy barrier. This work provides not only prospective insight into the effect of acid-base sites on the catalytic capacity but also a guide for the rational design of efficient ABPC.