Enhanced catalytic upgrading of glycerol into high value-added H2 and propanediols: Recent developments and future perspectives

•Bioglycerol to carbon neutral H2 and C3-diols; value-added precursors for bio-industries.•Better understanding of noble and no-noble metals based γ-Al2O3 structure-activity relationships was addressed.•Main catalytic functionalities and reforming or hydrogenolysis performance were identified.•Advanced perspectives on reforming and hydrogenolysis topics were provided.