Pyrolysis of ZIF-8 to PdZn alloy nanoparticles on carbon doping with nitrogen for highly efficient electrocatalytic alcohol oxidation

Abstract

MOFs (metal-organic frameworks) materials have been widely applied in sensing and catalysis, with the advantages of large surface area, numerous active sites, controllable size and morphology. Herein, we report the preparation of the caged PdZn/NC catalysts with the PdZn alloy nanoparticles on carbon doping with nitrogen owing high electrocatalytic performance by using a hydrothermal synthesis and pyrolysis strategy. The caged structure and PdZn alloy are demonstrated by a series of advanced characterization techniques. The material combines the advantages of bimetallic alloy and MOFs cage structure to realize highly efficient electrocatalytic oxidation of ethanol oxidation reactions (EOR) and methanol oxidation reactions (MOR) simultaneously. Electrochemical test results show that PdZn/NC-2 has a mass activity of 2.41 A mg−1pd and 2.64 A mg−1pd for methanol and ethanol oxidation, respectively, which is 12.68 times (MOR) and 14.67 times (EOR) higher than that of commercial Pd/C. This is probably attributed to the cage-like structure of PdZn/NC separating the Pd nanoclusters, resulting in high Pd dispersion. Simultaneously, the electronic property of Pd is adjusted after the formation of the complete PdZn alloy, improving the desorption of the carbon-based intermediates from the Pd active sites. This increases the CO poisoning resistance, resulting in good alcohol electrocatalytic oxidation activity and stability.