Selective conversion of styrene oxide to 2-phenylethanol in cascade reactions over non-noble metal catalysts

Abstract

The catalytic hydrogenation of styrene oxide (SO) and phenylacetaldehyde (PAA) to 2-phenylethanol (2-PEA), with H₂ in a tri-phase system, was investigated under various reaction conditions using supported Co and Ni metal catalysts. The catalysts were produced from tri-component layered double hydroxides (i.e., hydrotalcite-like compounds (Ni)CoMgAl with 1 : 1 : 1 molar ratios), after calcination and reduction of the layered double hydroxides precursors. Among the tested solids, the metallic Co-based catalyst has proven to be an efficient material for the selective hydrogenation of PAA towards 2-PEA. Taking into account the high activity and selectivity of Al-SBA-15 for SO isomerization to PAA, a two-step process was proposed as an original and highly selective route for producing 2-PEA from SO. This process involves cheap catalysts and it includes a first step of SO isomerization reaction over a mild acid strength mesoporous solid followed by hydrogenation of the resulted PAA over a redox metallic catalyst.