Direct Transformation of Glycerol to Propanal using Zirconium Phosphate‐Supported Bimetallic Catalysts

Abstract Selective transformation of glycerol to propanal (PA) provides a feasible route towards the sustainable synthesis of high value‐added chemicals. In this work, zirconium phosphate (ZrP) was studied as support and Ru and Co as metal sites for glycerol hydrogenolysis in a continuous‐flow reactor. It was found that ZrP‐supported Co−O species had a moderate selectivity to PA (49.5 %) in glycerol hydrogenolysis. Notably, once Ru species were doped into CoO/ZrP, the resulting catalyst exhibited not only an outstanding catalytic performance for glycerol hydrogenolysis to PA (a selectivity of 80.2 % at full conversion), but also a high stability at least a 50 h long‐term performance. The spent catalyst could be regenerated by calcining in air to remove carbonaceous deposits. Characterization indicated that the acid sites on ZrP played a very critical role in the dehydration of glycerol into acrolein (AE), that the distribution of Co was uniform, basically consistent with that of Zr, P and Ru, and that an especially close contact between Co−O and Ru species was formed on Ru/CoO/ZrP catalyst. The further activity tests and characterizations confirmed that there was a strong interaction between the dispersed Co−O species and Ru 0 nanoparticles, which endowed Ru sites with high electronic density. This effect could play a role in facilitating the dissociation of H 2 , and thus in promoting the hydrogenation reaction. Besides, DFT calculations suggested that the Co−O species can adsorb more strongly the C=C bond of the intermediate AE on a highly coordinatively unsaturated Co (Co cus ) site and thus lead to preferential hydrogenation at the C=C bond of AE to PA.