Highly selective electrocatalytic hydrogenation of cinnamaldehyde over tin dioxide-supported palladium nanocatalysts

Selective hydrogenation of α, β-unsaturated aldehydes has always been a hot research topic owing to favorable thermodynamics in CC hydrogenation. In this work, a series of Pd/SnO₂ nanocatalysts were facilely synthesized under mild conditions, via the reduction of Na₂PdCl₄ by dimethylaminoborane. Under galvanostatic electrolysis at 3.33 mA cm^?2 for 8 h, the selective conversion of cinnamaldehyde (CAL) was achieved over Pd/SnO₂-coated carbon fiber in neutral phosphate buffer, giving the cinnamyl alcohol (COL) selectivity of 78.85% at the conversion of 84.88%. The Pd/SnO₂ nanocatalysts outperform commercial Pd/C catalysts, showing high COL selectivity and faradaic efficiency. The cathodic reduction potential of CAL over Pd_4·3/SnO₂ occurs at ?0.92 V. The SnO₂ support is beneficial to promote the CO adsorption of CAL and lower the HER activity of Pd nanocatalysts, thereby contributing to superior activity of Pd_4·3/SnO₂ for selective hydrogenation of CAL.