Composition control of Pd-based bimetallic alloys to boost selective hydrogenation of furfural in aqueous micelles

Abstract

Composition control of bimetallic alloys to regulate the hydrogenation of furfural into high value-added derivatives is an important strategy for catalyst design, but remains a great challenge. In this work, we present a simple and sustainable strategy to construct Pd-based bimetallic alloys by reducing metal precursors dissolved in an aqueous solution of the sugar-based surfactant GluM. An obvious elemental composition-dependent selective hydrogenation of furfural in GluM aqueous micellar solution was observed – the Pd₁Cu₉ alloy exhibits a remarkable selectivity (99.9%) to furfural alcohol, whereas the Pd₁Ni₃ alloy can achieve deep-hydrogenation to tetrahydrofurfuryl alcohol with a high selectivity (96.2%). Experimental and theoretical investigation indicated that the excellent selectivity was attributed to the alloy effect and solvent effect, which provide different dissociative adsorption abilities of H₂ on the surface and the hydrogen bonding interactions facilitating H transfer in aqueous micelles, respectively. Notably, GluM micelles are not only employed to stabilize Pd-based bimetallic alloys, but also to enrich the furfural in water to improve the hydrogenation catalytic activity. Besides, this work on bimetallic alloy composition and H-shuttle in aqueous phase provides a new research direction for selective hydrogenation of furfural.