Study On Electrocatalytic Dehydrogenation Of Prime Amine Coupling Hydrogenation Of Organic Substrates

During the last decade,electrocatalytic oxygenation of organic compounds to value-added products with water as oxygen source has started to attract increased attention.To date,the majority of literature reports have focused on conversions efficiencies and selectivities,while the water active process,the catalytic active sits and the oxygen atom transfer mechanism are ambiguity.In electrocatalytic oxygenation reactions,protons are generated as a by-product.Thus,both catalytic efficiency and electron economy could be improved by pairing organic oxygenation with a rate-matched organic hydrogenation to create sustainable chemical synthesis strategies.In this paper,non-precious metal electrodes containing different elements are prepared,including Ni2P/NF?Ni3S4/NF?Ni(OH)2/NF?NixB/NF?Fe(OH)2/Pt?CoP/NF and MnO2/FTO electrodes.Using p-methoxybenzylamine as the model organic substrate to explore the activity,selectivity and Faraday efficiency of the oxidation of organic substrates in alkaline solutions over the above electrodes.The experimental results prove that nickel-based materials have a special response to the oxidation of p-methoxybenzylamine.Using water as oxygen source,the oxidation of p-methoxybenzylamine was catalyzed by NiBx/NF electrode in 0.1 M KOH aqueous solution with a conversion of 99.6%and Faraday efficiency of approximately 99.3%.Open-circuit potential versus time experiment and in situ Raman spectroscopy suggest that Ni3+OOH is the active intermediate during the oxidation of p-methoxybenzylamine.In the process of electrodehydrogenation of p-methoxybenzylamine,protons are formed as by-products,the reduction of p-nitrophenol is selected as cathode reaction to consume the protons generated in the electrocatalytic dehydrogenation of p-methoxybenzylamine.The paired system was constructed at constant potential for 140 min,conversions and selectivities of 98%were obtained for p-methoxybenzylamine oxidation at anode and the simultaneous p-nitrophenol hydrogenation at cathode.The new-type coupled electrolyzer constructed in this thesis,using water as hydrogen and oxygen sources,realizes the simultaneous production of value-added chemicals at both electrodes.