Fig. 3: Mechanism exploration of Al2O3-based Ru catalysts for amine-assisted CO2 hydrogenation.

a Schematic illustration of the influence of an excess CO2 atmosphere during the N-formylation of morpholine. b Catalytic conversion and selectivity of Ru-2 within 2 h over the batches shown in a, where the conversion was controlled ~20%. c H2-TPR profiles of the three catalysts. d Catalytic yield in two reactions with hydrogen and deuterium and the corresponding KIE values.