Efficient catalytic removal of formaldehyde at room temperature using AlOOH nanoflakes with deposited Pt

• AlOOH nanoflakes with deposited Pt were prepared and tested as catalysts.
• Pt/AlOOH showed a higher activity for HCHO oxidation than Pt/Al2O3 and Pt/TiO2.
• Surface hydroxyls and surface area affect the catalytic performance of Pt/AlOOH.
• Formate was found as the main intermediate in catalytic oxidation of HCHO over Pt/AlOOH.

Mesoporous AlOOH with deposited Pt (Pt/AlOOH) catalyst was prepared by combining the microemulsion-assisted synthesis of AlOOH nanoflakes with NaBH4-reduction of Pt precursor, and exhibited a remarkable catalytic activity as well as stability for elimination of formaldehyde (HCHO) vapor at room temperature. As compared to Pt deposited on calcined AlOOH (Pt/AlOOH-c), Pt on a commercial Al2O3 (Pt/c-Al2O3) and Pt on P25 (Pt/TiO2), the Pt/AlOOH nanoflakes showed the highest catalytic activity toward decomposition of HCHO at room temperature. The excellent performance of Pt/AlOOH nanoflakes could be attributed to the abundance of surface hydroxyls, high dispersion of Pt nanoparticles, excellent adsorption performance of AlOOH, and its high specific surface area and large pore volume. The mechanism of HCHO decomposition was investigated with respect to the behavior of adsorbed intermediates on Pt/AlOOH surface at room temperature using in situ DRIFTS. The result suggests that surface formate is the main reaction intermediate during the HCHO oxidation and it could be directly oxidized to CO2 in the presence of O2. By taking advantage of high adsorption affinity of AlOOH nanoflakes and excellent catalytic activity of Pt nanoparticles toward HCHO it was possible to design a superior nanostructured catalyst for room temperature decomposition of HCHO. This strategy can be also used to fabricate novel nanostructured catalysts for advanced applications such as environmental remediation.

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