Correlation among preparation methods/conditions, physicochemical properties, and catalytic performance of Rh/hydroxyapatite catalysts in N2O decomposition

•Morphology controlled hydroxyapatite (HAP) samples were prepared hydrothermally.•HAP supported Rh catalysts are efficient for N2O decomposition.•The activity is correlated with the basicity and amount of adsorbed O2.

Three hydroxyapatite (HAP) supported rhodium catalysts (i.e., Rh/HAP-PEG-200, Rh/HAP-EDTA-200, and Rh/HAP-EDTA-100) were prepared by loading Rh(NO3)3 onto HAP supports prepared hydrothermally at 200 or 100 °C in the presence of PEG or EDTA additive, followed by calcination at 500 °C. For comparison, an additional Rh/HAP-normal catalyst was prepared using a conventional HAP support prepared by precipitation. Different preparation methods/conditions were found to influence the physicochemical properties (e.g., micro-morphology, basicity, concentration of surface hydroxyls, oxygen-desorption property) of HAP supports and/or Rh/HAP catalysts. The activities of these catalysts in N2O decomposition follow the sequence of Rh/HAP-PEG-200 > Rh/HAP-EDTA-200 ≈ Rh/HAP-normal > Rh/EDTA-100. The correlation among preparation methods/conditions, physicochemical properties, and catalytic performance of Rh/HAP catalysts was investigated in detail.

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