Synthesis of Sequence-specific Poly(ester-carbonate) Copolymers via Chemoselective Terpolymerization Controlled by the Stoichiometric Ratio of Phosphazene/Triethylborane

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• Abstract:Electrocatalytic oxygen reduction(ORR) via the 2e~-pathway to form H_2O_2 in acidic medium has attracted extensive attention.However,the low activity,insufficient selectivity and high cost of catalysts have been the bottlenecks.Herein,CoSe_2 with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH_4-induced CoSe_2 phase transition from orthorhombic to cubic phase with more Se deficiency.The cubic phase CoSe_2 with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of ~*OOH and ~*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_2O_2.The onset potential is as low as 0.73 V vs.reversible hydrogen electrode(RHE),the H_2O_2 selectivity is 84%(0 V vs.RHE),and the average electron transfer number is about 2.3.Furthermore,the H_2O_2 yield measured using a flow cell is as high as 115.92 mmol·g_(cat).~(-1)·h~(-1) and the Faradaic efficiency is 70% at 0 V vs.RHE,which presents high potential in electrocatalytic acidic ORR to H_2O_2 and organic pollutant degradation using the electronFenton process.
• Volume:v.43
• Issue:02
• Translation or Not:no