Surface studies of carbon impregnated with various metals

The first part of this thesis deals on structural investigation of metal impregnated carbons (Ni, Cu, Zn, Cd) using different techniques such as nitrogen adsorption, mercury porosimetry, temperature programmed reduction (TPR), X-ray diffraction, thermal analysis and scanning electron microscopy. The result revels that metal resides are present on the surface of active carbon in the dispersed forms leading to an appreciable pore blockage. The second part deals with the adsorption of methanol, acetone, methyl formate and acetaldehyde on active carbon and metal doped carbons between 273 and 303 K. Thermodynamic parameters such as free energy, enthalpy and entropy of adsorption are also computed using a Virial isotherm expression and are interpreted. It is observed that metal dopant/active carbon systems are synergic, exhibiting more adsorption affinity for different organic vapours than sum of the individual constituents. Results show that an increase in adsorption affinity for metal doped carbons is not due to configurational factors affecting the entropy of adsorption but because of large exothermicity in the enthalpy of adsorption. (Orig./A.B.)