Abstract The present work reports on the morphological influence of catalyst on oxygen reduction reaction (ORR). As a catalyst, Prussian blue analog structured nickel hexacyanoferrate (Ni-HCF) with two distinct morphologically controlled frameworks, viz. granular crystalline bulk film and rose-petal like structured thin film having smooth surface, are synthesized via controlled anodization route, and their morphological influence on the ORR is investigated. In addition, the influence of addition of carbon black, which is commonly used as catalytic dispersing support, is also studied on the catalytic mechanism for the ORR. Based on the hydrodynamic voltammetry of the electrocatalytic films on rotating disk electrode, the number of electrons involved in the reduction of an O2 molecule, and the kinetic current density of the reaction are estimated. While the pristine Ni-HCF frameworks based catalyst, regardless of their morphology, demonstrates the direct reduction of O2 with participation of 4 electrons, the frameworks when mixed with carbon black as support diverts the reduction via two steps with participation of 2 electrons at each step. A larger kinetic current density is, however, obtained in the case of granular crystalline bulk film of the Ni-HCF frameworks.

中文翻译：

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电化学阳极氧化法合成的镍基普鲁士蓝类似物骨架的氧还原反应

摘要 目前的工作报告了催化剂对氧还原反应（ORR）的形态影响。作为催化剂，普鲁士蓝类似物结构化了六氰基铁酸镍 (Ni-HCF)，具有两种不同的形态控制框架，即。通过受控的阳极氧化途径合成了具有光滑表面的颗粒状结晶体膜和玫瑰花瓣状结构薄膜，并研究了它们对 ORR 的形态影响。此外，还研究了添加常用作为催化分散载体的炭黑对ORR的催化机理的影响。基于旋转圆盘电极上电催化膜的流体动力学伏安法，估计参与 O2 分子还原的电子数和反应的动力学电流密度。虽然基于原始 Ni-HCF 框架的催化剂，无论其形态如何，都表明 O2 在 4 个电子的参与下直接还原，当与作为载体的炭黑混合时，框架通过两个步骤转移还原，每一步有 2 个电子参与. 然而，在 Ni-HCF 骨架的粒状结晶体膜的情况下获得了更大的动态电流密度。