Highly recyclable palladium ion substituted TiO2 as the versatile ligand-free catalyst for the selective oxidation of alcohols and the reduction of nitroarenes

A noble metal ionic catalyst, Ti0.97Pd0.03O1.97 is synthesized by the solution combustion method with an average crystal size of 5 nm. The robustness of the catalyst is explored in both alcohol oxidation and aromatic nitro reduction reactions. This catalyst is effective in the selective oxidation of primary alcohol to aldehyde. Efficient transformation of various alcohols to carbonyl compounds is achieved in a short reaction time. The reduction of diverse aromatic nitro compounds is carried out in the presence of NaBH4 and H-2 as hydrogen sources. The solvent-free reduction is also carried out with a good yield. The present catalyst shows selectivity in the nitro reduction more favorably in the presence of the carbonyl group also. The recycling is carried out by easily employing catalyst-coated cordierite monolith in oxidation and reduction reactions, up to 10 cycles.

Automated summary

A noble metal ionic catalyst, Ti0.97Pd0.03O1.97, with an average crystal size of 5 nm, was synthesized using the solution combustion method. The robustness and efficiency of this catalyst were investigated in alcohol oxidation and aromatic nitro reduction reactions.