Preparation and characterization of supported noble metal catalysts synthesized by electroless deposition method

Electroless deposition (ED) is one of the viable processes that can be used to achieve uniform and high dispersion of metal over support, Catalyst synthesis by conventional method such as wet impregnation and ion exchange method has limitations in terms of low dispersion and weaker interaction between metal and support. In the present work, electroless deposition method was investigated for the preparation of supported noble mono-metallic catalyst and was compared with that prepared by conventional wetness impregnation. Al(NO₃)₃.9H₂O was used as alumina precursor for the support material while H₂PtC₁₆ was used as metal precursor. The XRD studies revealed that the metals were in well dispersed state. In the EDS ampping, platinum appeared to be clustered in catalysts prepared by impregnation, whereas, it was in much uniform and well dispersed state in catalysts synthesized by ED method. Loading linearly increased with concentration of metal precursor for catalysts in the studied concentration range. Loading increased with increasing concentration of reducing agent but remained unchanged on changing the sequence of reagent addition. However, more metallic platinum was deposited when reducing agent was added to alumina prior to platinum precursor