Process for the preparation of nanocrystalline PT—CE oxide catalyst for the selective hydrogenation of phenol and its derivatives

摘要

The present invention provides a process and catalyst for the conversion of phenol and its derivatives to cyclohexane and cyclohexanol. The process provides a direct single step for selective hydrogenation of phenol and its derivatives over Pt—Ce oxide catalyst. The process provides a phenol conversion of 50 to 100% and selectivity of hydrogenated product up to 98%.

主权项

1. A process for the preparation of nanocrystalline Pt—Ce oxide catalyst wherein the said process comprising the steps of
(a) mixing a salt of Cerium (Ce), a surfactant and water, with constant stirring for 2-4 h at a range of 35-45° C. while maintaining pH in the range of 8-9 to obtain a gel and further solidifying the gel by autoclaving the gel at temperature ranging between 150-180° C. for 7-10 days to obtain a solid; (b) filtering out and washing the solid as obtained in step (a) with ethanol and drying in an oven at a temperature range of 100-120° C. for a period ranging between 6-18 h followed by calcining the dried product at temperature range of 450-750° C. for a period ranging between 4-10 h to obtain Ce oxide; (c) preparing a solution by stirring Ce oxide as obtained in step (b) in ethanol for a period ranging between 30-120 min at temperature ranging between 30-40° C. (d) preparing second solution by stirring ethanol, water, CTAB (cetyltrimethyl ammonium bromide) and platinum (Pt) salt by stirring at temperature ranging between 30-40° C. until the solution becomes homogeneous; (e) mixing solution as prepared in step (d) with the solution as prepared in (c) dropwise and stirring for a period ranging between 30-120 minute at temperature ranging between 30-40° C. followed by adding hydrazine and stirring for 1-2 h at 30-40° C. and subsequently evaporating to dryness at 60-100° C. and further drying at 100-120° C. for 4-12 h then calcing in air atmosphere for 4-6 h at 450-750° C. to obtain nanocrystalline Pt—Ce oxide catalyst.