Abstract

Two types of apatite supports including hydroxyapatite (HAP) and fluorapatite (FAP) were prepared by the co-precipitation method. Supported Co catalysts with the above carriers were synthesized from Co(NO₃)₂·6H₂O via the impregnation method. The catalytic activity for N₂O decomposition was investigated using a continuous flowing microreactor system. The catalytic results demonstrated that the Co/HAP exhibited more excellent catalytic activity as well as the impurity gas (H₂O, O₂, and NO) resistance capability than the Co/FAP in the temperature range of 300–600 °C. Furthermore, the physicochemical properties of Co/HAP and Co/FAP were determined by several relevant characterization methods. The obtained experimental results revealed that Co/HAP possessed larger specific surface area, more ion-exchanged Co²⁺ and stronger oxygen desorption capacity than Co/FAP, which are the key factors for high N₂O decomposition activity. Moreover, compared with Co/FAP, Co/HAP has not only more basic content, but also higher basic site density, which may be also conducive to enhance the electron donating ability of Co²⁺, thereby promoting the N₂O catalytic decomposition.

Graphic Abstract

中文翻译：

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磷灰石负载的Co 3 O 4催化剂对N 2 O分解的影响

摘要

通过共沉淀法制备了两种类型的磷灰石载体，包括羟基磷灰石（HAP）和氟磷灰石（FAP）。通过浸渍法由Co（NO ₃）₂ ·6H ₂ O合成具有上述载体的负载型Co催化剂。使用连续流动的微反应器系统研究了N ₂ O分解的催化活性。催化结果表明，Co / HAP以及杂质气体（H ₂ O，O ₂在300–600°C的温度范围内具有比Co / FAP更高的电阻性能。此外，通过几种相关的表征方法确定了Co / HAP和Co / FAP的理化性质。实验结果表明，Co / HAP比N / O具有更大的比表面积，更多的离子交换Co ²⁺和更强的氧气脱附能力，这是高N ₂ O分解活性的关键因素。而且，与Co / FAP相比，Co / HAP不仅具有更高的碱性含量，而且具有更高的碱性位点密度，这也有利于增强Co ²⁺的电子给体能力，从而促进了N ₂ O的催化分解。

图形摘要