• Palladium is a catalyst used in variety of reactions involving electro-oxidation and reduction.
• Solid polymer electrolyte (SPE) reactors are made of palladium catalysts and allow facile transport of ionic species to the catalyst surface through the membrane  under an applied potential.
• However, the control over morphology of palladium nanostructures on carbon or CNTs based substrates has been difficult, especially with the conventional  method of the chemical reduction.
• Hence, there is a demand of a new method to address  the above mentioned issues.

A method of preparing palladium dendrites

Coating carbon on a carbon paper by  dispersing carbon powder in a mixture of  an ionomer and a solvent followed by ultrasonic.

Activating carbon surface electro-  chemically by potential cycling in an acidic  electrolyte

Electrodepositing  palladium  on  the electrochemically activated carbon coated carbon paper by potential cycling using palladium chloride as a precursor at a  concentration of 1.0 mM

• The carbon paper  is  Teflonised  Carbon,  including Vulcan XC-72R and Ketjen Black.

• The ionomer is Nafion, and Isopropanol is solvent.
• The carbon coated carbon paper is air dried.
• The acidic electrolyte used for electrochemical activation of carbon is sulfuric acid with a strength of 0.5 m, that increases  hydrophilicity and generates surface defects  on carbon substrate.
• The acidic medium used for palladium dendrites electro-deposition is perchloric acid with 0.01 m strength.
• By increasing cycles of electro-deposition from 5  to   25   increases   the  growth,   size   & strength of electro-deposited palladium.
• The three-dimensional dendrites with complete coverage is prepared by increasing deposition cycles to 25 on the carbon paper.