Influence of Catalyst Reduction Temperature on Autogenous Glycerol Hydrogenolysis over NiAl Catalyst

Abstract

Autogenous glycerol hydrogenolysis to 1,2-propanediol by aqueous phase reforming (APR) was investigated over supported nickel catalysts. Effect of reduction temperature on physico-chemical properties of catalysts played a significant role in tuning conversion and product selectivities. The formation of nickel aluminate (NiAl 2 O 4 ) spinel phase during catalyst reduction led to rearrangement of Ni species to obtain small and stable Ni particles. The catalyst activation temperature alters the extent of reduction of multivalent Ni species (Ni 0 , Ni + 2/ + 3 ) which facilitated glycerol dehydration and hydrogenation while suppressing CÀ C cleavage and thus avoiding undesirable side products. Additionally, presence of moderate BrØnsted/Lewis acid ratio of the catalyst promoted higher 1,2-PDO selectivity. In-situ glycerol hydrogenolysis involves glycerol dehydration to acetol with simultaneous reforming to H 2 and CO 2 and this hydrogen converts acetol to 1,2-PDO.

A review on non-noble metal catalysts for glycerol hydrodeoxygenation to 1,2-propanediol with and without external hydrogen

“…The catalyst characterization data revealed that the formation of NiAl 2 O 4 spinel phase, smaller nickel particles ( < 8 nm), presence of moderate acid sites and the optimal B L −1 ratio of 1.35 are the key factors for the high catalytic performance. 202…”