Metal-organic interface engineering for boosting the electroactivity of Pt nanodendrites for hydrogen production

Abstract Recently, the surface chemical functionalization and morphology control of precious metal nanostructures have been recognized as two efficient strategies for improving their electroactivity and/or selectivity. In this work, 1, 10-phenanthroline monohydrate (PM) functionalized Pt nanodendrites (Pt-NDs) on carbon cloth (CC) (denoted as PM@Pt-NDs/CC) and polyethylenimine (PEI) functionalized Pt-NDs on CC (denoted as PEI@Pt-NDs/CC) are successfully achieved by immersing Pt-NDs/CC into PM and PEI aqueous solutions, respectively. PEI functionalization of Pt-NDs/CC improves its electroactivity for hydrogen evolution reaction (HER) due to local proton enrichment whereas PM functionalization of Pt-NDs/CC improves its electroactivity for formic acid oxidation reaction (FAOR) by facilitating dehydrogenation pathway. With such high activity, a two-electrode electrolyzer is assembled using PM@Pt-NDs/CC as the anodic electrocatalyst and PEI@Pt-NDs/CC as the cathodic electrocatalyst for electrochemical reforming of formic acid, which only requires 0.45 V voltage to achieve the current density of 10 mA cm−1 for high-purity hydrogen production, much lower than conventional water electrolysis (1.59 V). The work presents an example of interfacial engineering enhancing electrocatalytic activity and indicates that electrochemical reforming of formic acid is an energy-saving electrochemical method for high-purity hydrogen production.