Nitrogen doped graphene supported Pd as hydrogen evolution catalyst for electrochemical methanol reformation.

Abstract Electrochemical methanol reformation (ECMR) method has been identified as one of the most effective method for on-site hydrogen production. However, concentrated research towards the development of efficient inexpensive hydrogen evolution reaction (HER) electrocatalyst holds the pivotal role in realizing the hydrogen economy. In this context, for the first time N-graphene supported Pd (Pd/NG) was synthesised and employed as an HER catalyst in ECMR process. N-graphene was synthesised by modified Hummer's method followed by Pd deposition through hydrothermal route. The electrocatalytic activity of Pd/NG for hydrogen evolution was evaluated by CV and LSV techniques. Tafel slope of Pd/NG and Pt/C was calculated from LSV curves and was found to be 33 and 31 mV/decade, respectively. Exchange current density was found to be 3.6 and 3.2 × 10−4 A cm−2 for Pd and Pt catalysts, respectively. The enhanced electrocatalytic activity is majorly attributed to the N-doping and uniform distribution of Pd nano particles on graphene. Further, the performance of Pd/NG was also evaluated in single ECMR cell using Pt–Ru/C at anode and Pd/NG at cathode as electrocatalysts. The results indicated the suitability of Pd/NG as cathode electrocatalyst for HER in ECMR process. Graphical abstract Image 1 Highlights • Synthesis of nitrogen doped graphene supported Pd electrocatalyst (Pd/NG). • Physico-chemical and electrochemical characterization of Pd/NG electrocatalyst. • Hydrogen evolution reaction with lower onset potential, less Tafel slope and high exchange current density. • Performance evaluation of Pd/NG as hydrogen evolution catalyst in electrochemical methanol reformation. [ABSTRACT FROM AUTHOR]