HYDROGENATION OF CINNAMALDEHYDE BY PLATINUM SUPPORTED ON 2D AND 3D TRANSITION METAL SULFIDES

Abstract

The selective hydrogenation of cinnamaldehyde (CAL), a model α, β-unsaturated aldehyde, yields valuable products such as cinnamyl alcohol (COL) and hydrocinnamaldehyde (HCAL). Pt-based catalysts supported on transition metal dichalcogenides (MoS₂, WS₂, and their composite) in bulk forms and their exfoliated counterparts were synthesized using microwave-assisted and wet impregnation methods. Characterization (SEM/EDS, TEM, XRF, XRD, BET) confirmed ~9 wt.% Pt loading, preserved layered structures, and well-dispersed nanoparticles. Catalyst based on 2D supports provided finer Pt dispersion (2–6 nm), with microwave synthesis yielding smaller, more uniform particles, especially in Mo-W composite. Catalytic testing demonstrated that both activity and selectivity were strongly influenced by the support composition and morphology, with 2D Mo-W composite outperforming MoS₂ and WS₂. All catalysts predominantly promoted selective C=O hydrogenation to COL, while HCAL, and HCOL remained minor products. The best performance was achieved with Pt supported on 2D Mo-W-S composite prepared by microwave-assisted synthesis, delivering 75% CAL conversion with COL selectivity and yield achieved within 6 h, 64% and 48%, respectively.