Synthesis And Electrocatalytic Properties Of Carboxylic Acid And Nitrogen Rich Metal Organic Framework Derivatives

Hydrogen is a clean,green and renewable new energy source.Electrocatalytic hydrolytic hydrogen production is widely concerned because of its simple and convenient operation,but its wide application is limited due to the high price and limited resources of precious metal catalysts.The development of efficient and stable non-noble metal electrocatalysts remains a great challenge.Metal-organic framework materials are widely used in adsorption,catalysis and other fields due to their adjustable structure,large specific surface area and rich pore size.Electrocatalysts with excellent performance can be obtained by synthesizing metal-organic framework materials with transition metals and organic ligands and modifying them by carbonization,phosphating and sulfurization.In this study,two different catalysts were synthesized by two-step method using carboxylic acid and nitrogen rich ligands and transition metals.They were applied to hydrogen evolution reaction(HER),oxygen evolution reaction(OER)and oxygen reduction reaction(ORR),respectively.They were used to study the overall water splitting and zinc air batteries.1、Here an efficient hollow sea urchin shaped water splitting catalyst was prepared by coordination confinement pyrolysis strategy,in which the superminiature Co/Ni alloy(ca.5 nm)was embedded into the nanorods assembly unit successfully.This as-synthesized catalyst not only reveals satisfactory catalytic efficiencies with 70 and 296 mV overpotentials for HER and OER at the current density of 10 mA·cm-2,but also demonstrates the total stabilities for HER,OER and overall water splitting after long-term electrolytic process with the negligible potentials increase by 2.8%,2.9%and 1.8%.Therefore,the catalyst integrating superminiature Co/Ni alloy particles,hollow structure and slender nanorods could provide a new idea to design and prepare other electrocatalysts.2、The partial 2-methylimidazole ligand in ZIF-8 was exchanged into 5-methyltetrazole by solvent assisted ligand exchange method,and Fe ions were doped into it to obtain hollow polyhedra structure with rough surface.When tested in 0.1 M KOH saturated with O2,the half-wave potential is 0.95 V and the diffusion-limited current density is 7.02 mA·cm-2,showing good methanol tolerance and stability.It was prepared as a disposable zinc-air battery with an open circuit voltage of 1.55 V,a peak power density of 340 mW·cm-2,a discharge capacity of 380 mA·cm-2 and a specific capacity of 692 mAh·gzn-1.Figure[26]Table[9]Reference[137]...