【摘要】 析氧反应（OER）由于动力学缓慢，在苛刻的酸性环境中严重依赖贵金属Ir或Ru催化剂，因而阻碍了电解水制氢技术的工业化应用，寻求一种低成本、高活性、高稳定性的酸性水电解催化剂迫在眉睫.普鲁士蓝及其类似物（PBAs）不仅可作为N掺杂C的前驱体，由于其具有可调的过渡金属组成及大比表面积等优点，还可以实现对贵金属Ir基催化剂的高度分散，从而达到降低电极成本的目的.本文中通过热解PBAs、双氰胺和IrCl₃的混合物制备了系列Ir/Co@NCNT复合催化剂，其中Ir/Co@NCNT（Ir%=18%（wt））由螺旋状相互缠绕的NCNTs包裹IrCo合金纳米颗粒组成，NCNTs作为保护层，可以防止内部金属与电解液直接接触，其三维网络结构促进了反应物的传质及气体的释放，同时Ir与Co之间的协同作用以及NC基体与金属（IrCo）的相互作用进一步提升了催化剂的活性.在0.5 mol/L H₂SO₄中，Ir/Co@NCNT在10 mA·cm^-2时HER和OER的过电位分别为5 mV和330 mV,全水解的电压仅为1.566 V,并具有较好的稳定性.更多还原

【Abstract】 Due to the slow kinetics, the anodic oxygen evolution reaction（OER） relies heavily on precious metals（i.e. Ir or Ru） in harsh acidic environment, which hinders the industrial application of water electrolysis technology for hydrogen production. Therefore, it is urgent to seek a low-cost, high activity and robust electrocatalyst for acidic water splitting. Prussian blue and its analogues（PBAs） not only serve as the source of N-doped C, but also achieve the highly dispersion of precious metal Ir-based catalysts due to their advantages of adjustable transition metal speciesand large specific surface area. In this work, a series of Ir/Co@NCNT composite catalysts were prepared by pyrolysis of the mixture of PBAs, dicyanodiamide and IrCl₃. Ir/Co@NCNT（Ir%=18%（wt）） was composed of IrCo alloy nanoparticles wrapped by spirally wound NCNTs. NCNTs served as the protective layer for preventing the direct contact of the internal metals with the electrolyte, and the three-dimensional network structure promoted the mass transfer of reactants and gas release. Meanwhile, the synergistic effect between Ir and Co, and the interaction between NC matrix and metal（IrCo） further enhanced the catalytic activity. In 0.5 mol/L H₂SO₄, the overpotential of HER and OER at 10 mA·cm^-2 on Ir/Co@NCNT was 5 mV and 330 mV respectively, and the electrolytic voltage for the total water splitting was only 1.566 V. Ir/Co@NCNT also exhibited a good stability for water splitting in acidic medium.更多还原