Kinetic study of C4 polyol hydrogenolysis on Rh promoted catalyst

MARÍA EUGENIA SAD; CRISTINA PADRÓ; EMANUEL VIRGILIO

Congreso; 17th INTERNATIONAL CONGRESS ON CATALYSIS; 2020

Erythritol (ERY, C4H10O4)is a promising intermediate produced by fermentation of sugars that can beobtained from non-edible biomass derives. By C-O hydrogenolysis, valuablebutanediols (BDOs) can be obtained but their consecutive C-O hydrogenolysisproduces butanols and butane, while C-C cleavage leads to lower carbon products(C2-C3), which are less valuable compounds and therefore should be avoided.Butanediols, have many applications such as food flavorings, inks, perfumes,fumigants and production of resins. Polyol hydrogenolysis has been previouslystudied, particularly using glycerol as reactants in aqueous solution toproduce 1,2-propanediol  and 1,3-propanediol[1]. Typically, noble metal/support catalysts are used for hydrogenolysis reactions.Pt, Ru, Rh, and Ir have been investigated but Pt was less active, while Ru,often promotes excessive C?C cleavage. To prevent the break of the carbonchain, an oxophilic promoter (Re, Mo or W) is added to the noble metalresulting in an improvement of the selectivity to the C-O hydrogenolysis [2].Rh/ReOx bimetallic catalysts supported onTiO2 or ZrO2 were studied to promote the ERYhydrogenolysis to BDOs and the highest selectivity obtained to butanetriol andbutanediol was 37% and 29% respectively, at 80% ERY conversion (200°C, 120 barH2) when using 3.7wt%Rh-3.5wt.%ReOx/ZrO2 [3].The effect H2 partial pressure on ERY initial rate was previouslydiscussed while the effect of ERY initial concentration and kinetic studies forBDO formation from ERY is still lacking. Therefore, in this work we focused onthe C-O hydrogenolysis of ERY using Rh/ReOx/TiO2 with ̴1.8wt% metal contents and 15-35 bar of hydrogen in order to selectively produceBDO. Also, we compared the catalytic behavior of mono and bimetallic catalystsand estimated the reaction orders for ERY and H2 as well asactivation energy from kinetic experiments.