The electrochemical reforming of glycerol at Pd nanocrystals modified ultrathin NiO nanoplates hybrids: An efficient system for glyceraldehyde and hydrogen coproduction

The glycerol electro-oxidation reaction (GEOR) is a green and promising method for the glyceraldehyde production. In this work, Pd nanocrystals (Pd-NCs) modified ultrathin NiO nanoplates (NiO-uNPs) hybrids (Pd-NCs/NiO-uNPs) are successfully synthesized using successive cyanogel hydrolysis, chemical reduction, and calcination treatment methods. Various electrochemical measurements and physicochemical characterization results demonstrate that Pd-NCs/NiO-uNPs hybrids have excellent electrocatalytic performance for both GEOR and hydrogen evolution reaction (HER) in alkaline medium, which benefit from the large specific surface area, uniform distribution of Pd-NCs, and the modified electronic structure of Ni atoms. At Pd-NCs/NiO-uNPs hybrids, only 1.43 V is needed to obtain the current density of 100 mA∙cm⁻² for GEOR, much lower than that for oxygen evolution reaction (1.82 V). In addition, Pd-NCs/NiO-uNPs hybrids exhibit better HER performance than commercial Pd/C electrocatalyst. As a result, the constructed Pd-NCs/NiO-uNPs||Pd-NCs/NiO-uNPs glycerol electrolyzer only requires 1.62 V electrolysis voltage to reach 10 mA∙cm⁻² current density, showing an energy-efficient and economy-competitive synthesis for the coproduction of glyceraldehyde and hydrogen.