Abstract
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•1,3-propanediol was produced from glycidol using Ni/saponites catalysts.•Ni wt% and acidity of saponites determined NiO reducibility in catalyst precursors.•Higher activity and propanediol selectivity was obtained at higher Ni loading.•An optimum distribution of metal and acid sites was crucial to 1,3-PD formation.•Glycidol can be an alternative to glycerol to produce 1,3-PD by hydrogenolysis.
This study explores the use of glycidol, as alternative to glycerol, to improve the selectively to 1,3-propanediol (PrD) by hydrogenolysis. The reaction was performed using Ni (with different Ni wt%) supported on an acid delaminated saponite catalysts which are cheaper compared to the expensive catalysts needed to favor the 1,3-PrD formation by glycerol hydrogenolysis. An increase in metallic area and a decrease in the catalyst acidity resulted in higher conversion and selectivity to propanediols (1,2-+1,3-PrD). An acid activation of glycidol during hydrogenolysis promoted the 1,3-PrD formation and increased the 1,3-PrD/1,2-PrD ratio. For the catalyst prepared with 40wt% Ni loading, an increase in the reaction temperature to 423 and 453K led to higher 1,3-PrD/1,2-PrD ratio. The highest 1,3-PrD yield (29%) and 1,3-PrD/1,2-PrD ratio (0.97) at total conversion were obtained at 453K, after 1h. The overall 1,3-PrD yield from glycerol, assuming a two-step synthesis (Glycerol→Glycidol→1,3-PrD) and a yield of 78% for the first step, should be around 23%. This value is comparable to that reported for the hydrogenolysis of glycerol using noble metal catalysts.