限域单原子催化剂的制备及其催化湿式氧化性能

Preparation and wet oxidation properties of a domain-confined single-atomic catalyst

摘要:

采用原位合成法将Ni单原子限域的Ni-NCNT碳纳米管结构架构到活性炭表面制备Ni-NCNT/AC催化剂载体，再利用浸渍法制备负载Ru金属催化剂（Ru@Ni-NCNT/AC），以降解乙酸废水。通过SEM、TEM、XAFS、XPS、H2-TPR和CO-DRIFTS等对样品的形貌、结构、元素价态、表面吸附和化学性质进行分析及DFT计算。结果表明，Ni单原子作为催化助剂，通过改变基底材料的电子特性从而促进表面贵金属发挥更高的催化氧化乙酸的活性。在温度250℃，压力6.5MPa条件下，连续运行10天，乙酸的去除率持续稳定在95 %以上，催化剂具有较高活性和良好的稳定性。

Abstract:

Ni-NCNT/AC catalyst support was prepared by in-situ synthesis of Ni single atom confined Ni-NCNT carbon nanotubes on the surface of activated carbon, and Ruthenium catalysts loaded on these support was prepared by impregnation method and degrade acetic acid wastewater.The morphology, structure, element valence, surface adsorption and chemical properties of the samples were analyzed and density functional theory(DFT) calculated by scanning electron microscope(SEM), transmission electron microscopy(TEM), X-ray absorption spectrum(XAFS), X-ray electron energy spectra(XPS),temperature-programmed reduction(H2-TPR) and Carbon monoxide diffuse reflectance infrared Fourier transform spectroscopy(CO-DRIFTS).The results show that Ni single atom as a catalytic promoter can promote the surface precious metals to play a higher catalytic activity for the oxidation of acetic acid by changing the electronic properties of the substrate material.Under the conditions of temperature 250℃, pressure 6.5MPa and continuous operation for 10 days, the removal rate of acetic acid remained stable at more than 95%, and the catalyst had high activity and good stability.