Surface titanium oxide loaded on a special alumina as high-performance catalyst for reduction of cinnamaldehyde by isopropanol

A nanocomposite catalyst with a nonstoichiometric titanium oxide loaded on a special nanotubular alumina(γ‐Al2O3‐nt)was developed and used to reduce cinnamaldehyde to cinnamyl alcohol with sacrificial isopropanol,i.e.,a Meerwein‐Ponndorf‐Verley type reaction.The deposition process produced a highly disperse layer of titanium oxide on the surface of aγ‐Al2O3‐nt support.After a reduction treatment,the as‐prepared TiOx/γ‐Al2O3‐nt was a highly efficient catalyst for the hydrogen transfer reaction between isopropanol and cinnamaldehyde.Selectivity for cinnamic alcohol was higher than99%and the conversion of cinnamaldehyde was higher than95%.The regular morphology of theγ‐Al2O3‐nt support with homogeneous surface sites and the uniformly dispersed titanium oxide featured a high concentration surface Ti(III)species.These factors contributed to the high performance of the TiOx/γ‐Al2O3‐nt catalyst.