Mechanistic insights into the hydroconversion of cinnamaldehyde using mechanochemically-synthesized Pd/Al-SBA-15 catalysts

Abstract

The hydroconversion of cinnamaldehyde as an α,β-unsaturated compound was studied using a simple and efficient hydrogen-donating protocol catalyzed by mechanochemically synthesized bifunctional Pd/Al-SBA-15 catalysts. Materials were characterized using TGA-TDA, nitrogen physisorption, TEM and EDX analyses. Catalytic results pointed to the presence of competitive pathways that are able to provide a selectivity switch from the expected fully hydrogenated aromatic ring (e.g. cyclohexane) and hydrogenated products (e.g. hydrocinnamaldehyde, cinnamyl alcohol and 3-phenylpropan-1-ol) to the unexpected ethylbenzene and oxalic acid products from hydrodeformylation and hydrocarboxylation reactions of cinnamaldehyde and formic acid, respectively.