Valorization of olive stones for the synthesis of phosphorus-modified porous carbons and their use as support of Pd particles for the oxidative condensation of furfural with ethanol

Abstract

Activated carbons have been synthesized by a pyrolytic treatment and a chemical activation with H3PO4 to give rise to amorphous graphite, with high micro-mesoporosity and Brönsted acid sites. These materials have been employed as supports to incorporate Pd species to be used as catalysts in the oxidative condensation of furfural with ethanol to obtain furan-2-acrolein (F2A), as main product. The catalytic results show that F2A is obtained at shorter reaction times, with a maximum yield of 45 % after 180 min at 150 °C. The catalytic studies at longer reaction time worsen the F2A yield due to undesired and uncontrolled condensation reactions, which lead to the formation of humins. On the other hand, it is demonstrated that the amount of oxidant (H2O2) and base (Na2CO3) must be modulated to attain an optimum F2A yield.